Style Change: NULL->nullptr

DOCS_PREVIEW= https://skia.org/?cl=1316233002

Review URL: https://codereview.chromium.org/1316233002

144 files changed, 422 insertions, 428 deletions

diff --git a/gm/aaclip.cpp b/gm/aaclip.cpp
index 7ede6a5fe1..b3c39b7b14 100644
--- a/gm/aaclip.cpp
+++ b/gm/aaclip.cpp
@@ -140,7 +140,7 @@ static void test_image(SkCanvas* canvas, const SkImageInfo& info) {
     newc->drawCircle(50, 50, 49, paint);
     canvas->drawBitmap(bm, 10, 10);
 
-    CGImageRef image = SkCreateCGImageRefWithColorspace(bm, NULL);
+    CGImageRef image = SkCreateCGImageRefWithColorspace(bm, nullptr);
 
     SkBitmap bm2;
     SkCreateBitmapFromCGImage(&bm2, image);
diff --git a/gm/aarectmodes.cpp b/gm/aarectmodes.cpp
index e0df7d84b1..fb5145bc5f 100644
--- a/gm/aarectmodes.cpp
+++ b/gm/aarectmodes.cpp
@@ -161,7 +161,7 @@ namespace skiagm {
                     SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
 
                     canvas->drawRect(bounds, fBGPaint);
-                    canvas->saveLayer(&bounds, NULL);
+                    canvas->saveLayer(&bounds, nullptr);
                     SkScalar dy = drawCell(canvas, mode,
                                            gAlphaValue[alpha & 1],
                                            gAlphaValue[alpha & 2]);
diff --git a/gm/aaxfermodes.cpp b/gm/aaxfermodes.cpp
index d33423a35e..9e07f8d751 100644
--- a/gm/aaxfermodes.cpp
+++ b/gm/aaxfermodes.cpp
@@ -161,7 +161,7 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         draw_pass(canvas, kCheckerboard_Pass);
-        canvas->saveLayer(NULL, NULL);
+        canvas->saveLayer(nullptr, nullptr);
 
         canvas->translate(kMargin, kMargin);
         draw_pass(canvas, kBackground_Pass);
diff --git a/gm/addarc.cpp b/gm/addarc.cpp
index 3bfed8d549..0d1ea93133 100644
--- a/gm/addarc.cpp
+++ b/gm/addarc.cpp
@@ -101,7 +101,7 @@ protected:
             SkPathMeasure meas(path, false);
             SkScalar arcLen = rad * R;
             SkPoint pos;
-            if (meas.getPosTan(arcLen, &pos, NULL)) {
+            if (meas.getPosTan(arcLen, &pos, nullptr)) {
                 canvas->drawLine(0, 0, pos.x(), pos.y(), measPaint);
             }
         }
diff --git a/gm/all_bitmap_configs.cpp b/gm/all_bitmap_configs.cpp
index 2fbd71de24..4cabf2ec9b 100644
--- a/gm/all_bitmap_configs.cpp
+++ b/gm/all_bitmap_configs.cpp
@@ -75,7 +75,7 @@ static void color_wheel_native(SkCanvas* canvas) {
     const SkScalar D = 0.3f * SkIntToScalar(SCALE);
     const SkScalar X = SkDoubleToScalar(D * sqrt_3_over_2);
     const SkScalar Y = D * SK_ScalarHalf;
-    sk_tool_utils::set_portable_typeface(&p, NULL, SkTypeface::kBold);
+    sk_tool_utils::set_portable_typeface(&p, nullptr, SkTypeface::kBold);
     p.setTextSize(0.28125f * SCALE);
     draw_center_letter('K', &p, SK_ColorBLACK, Z, Z, canvas);
     draw_center_letter('R', &p, SK_ColorRED, Z, D, canvas);
@@ -127,7 +127,7 @@ static SkBitmap indexed_bitmap() {
     SkAutoTUnref<SkColorTable> ctable(new SkColorTable(pmColors, SK_ARRAY_COUNT(pmColors)));
     SkImageInfo info = SkImageInfo::Make(SCALE, SCALE, kIndex_8_SkColorType,
                                          kPremul_SkAlphaType);
-    bm.allocPixels(info, NULL, ctable);
+    bm.allocPixels(info, nullptr, ctable);
     SkAutoLockPixels autoLockPixels1(n32bitmap);
     SkAutoLockPixels autoLockPixels2(bm);
     for (int y = 0; y < SCALE; ++y) {
@@ -155,7 +155,7 @@ DEF_SIMPLE_GM(all_bitmap_configs, canvas, SCALE, 6 * SCALE) {
     SkPaint p;
     p.setColor(SK_ColorBLACK);
     p.setAntiAlias(true);
-    sk_tool_utils::set_portable_typeface(&p, NULL);
+    sk_tool_utils::set_portable_typeface(&p, nullptr);
 
     sk_tool_utils::draw_checkerboard(canvas, SK_ColorLTGRAY, SK_ColorWHITE, 8);
 
diff --git a/gm/alphagradients.cpp b/gm/alphagradients.cpp
index b209cec9d1..71ec27c975 100644
--- a/gm/alphagradients.cpp
+++ b/gm/alphagradients.cpp
@@ -28,12 +28,12 @@ protected:
         SkPoint pts[] = { { r.fLeft, r.fTop }, { r.fRight, r.fBottom } };
         SkPaint paint;
         uint32_t flags = doPreMul ? SkGradientShader::kInterpolateColorsInPremul_Flag : 0;
-        SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, 2,
-                                                     SkShader::kClamp_TileMode, flags, NULL);
+        SkShader* s = SkGradientShader::CreateLinear(pts, colors, nullptr, 2,
+                                                     SkShader::kClamp_TileMode, flags, nullptr);
         paint.setShader(s)->unref();
         canvas->drawRect(r, paint);
 
-        paint.setShader(NULL);
+        paint.setShader(nullptr);
         paint.setStyle(SkPaint::kStroke_Style);
         canvas->drawRect(r, paint);
     }
diff --git a/gm/arithmode.cpp b/gm/arithmode.cpp
index 4b8194464f..53385ea6ab 100644
--- a/gm/arithmode.cpp
+++ b/gm/arithmode.cpp
@@ -31,7 +31,7 @@ static SkBitmap make_src() {
         SK_ColorTRANSPARENT, SK_ColorGREEN, SK_ColorCYAN,
         SK_ColorRED, SK_ColorMAGENTA, SK_ColorWHITE,
     };
-    SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
+    SkShader* s = SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
                                                  SkShader::kClamp_TileMode);
     paint.setShader(s)->unref();
     canvas.drawPaint(paint);
@@ -47,7 +47,7 @@ static SkBitmap make_dst() {
         SK_ColorBLUE, SK_ColorYELLOW, SK_ColorBLACK, SK_ColorGREEN,
         sk_tool_utils::color_to_565(SK_ColorGRAY)
     };
-    SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
+    SkShader* s = SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
                                                  SkShader::kClamp_TileMode);
     paint.setShader(s)->unref();
     canvas.drawPaint(paint);
@@ -105,13 +105,13 @@ protected:
         SkScalar gap = SkIntToScalar(src.width() + 20);
         while (k < stop) {
             SkScalar x = 0;
-            canvas->drawBitmap(src, x, y, NULL);
+            canvas->drawBitmap(src, x, y, nullptr);
             x += gap;
-            canvas->drawBitmap(dst, x, y, NULL);
+            canvas->drawBitmap(dst, x, y, nullptr);
             x += gap;
             SkRect rect = SkRect::MakeXYWH(x, y, SkIntToScalar(WW), SkIntToScalar(HH));
-            canvas->saveLayer(&rect, NULL);
-            canvas->drawBitmap(dst, x, y, NULL);
+            canvas->saveLayer(&rect, nullptr);
+            canvas->drawBitmap(dst, x, y, nullptr);
             SkXfermode* xfer = SkArithmeticMode::Create(k[0], k[1], k[2], k[3]);
             SkPaint paint;
             paint.setXfermode(xfer)->unref();
diff --git a/gm/astcbitmap.cpp b/gm/astcbitmap.cpp
index 8ee7746f61..bc5e1e978f 100644
--- a/gm/astcbitmap.cpp
+++ b/gm/astcbitmap.cpp
@@ -70,7 +70,7 @@ protected:
                 }
 
                 SkAutoTUnref<SkData> fileData(SkData::NewFromFileName(filename.c_str()));
-                if (NULL == fileData) {
+                if (nullptr == fileData) {
                     SkDebugf("Could not open the file. Did you forget to set the resourcePath?\n");
                     return;
                 }
diff --git a/gm/beziereffects.cpp b/gm/beziereffects.cpp
index 9edc11411a..ff75f74c66 100644
--- a/gm/beziereffects.cpp
+++ b/gm/beziereffects.cpp
@@ -121,12 +121,12 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        if (NULL == rt) {
+        if (nullptr == rt) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
         GrContext* context = rt->getContext();
-        if (NULL == context) {
+        if (nullptr == context) {
             return;
         }
 
@@ -159,7 +159,7 @@ protected:
                 {   // scope to contain GrTestTarget
                     GrTestTarget tt;
                     context->getTestTarget(&tt);
-                    if (NULL == tt.target()) {
+                    if (nullptr == tt.target()) {
                         continue;
                     }
                     GrPrimitiveEdgeType et = (GrPrimitiveEdgeType)edgeType;
@@ -269,12 +269,12 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        if (NULL == rt) {
+        if (nullptr == rt) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
         GrContext* context = rt->getContext();
-        if (NULL == context) {
+        if (nullptr == context) {
             return;
         }
 
@@ -307,7 +307,7 @@ protected:
                 {   // scope to contain GrTestTarget
                     GrTestTarget tt;
                     context->getTestTarget(&tt);
-                    if (NULL == tt.target()) {
+                    if (nullptr == tt.target()) {
                         continue;
                     }
                     GrPrimitiveEdgeType et = (GrPrimitiveEdgeType)edgeType;
@@ -512,12 +512,12 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        if (NULL == rt) {
+        if (nullptr == rt) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
         GrContext* context = rt->getContext();
-        if (NULL == context) {
+        if (nullptr == context) {
             return;
         }
 
@@ -548,7 +548,7 @@ protected:
                 {   // scope to contain GrTestTarget
                     GrTestTarget tt;
                     context->getTestTarget(&tt);
-                    if (NULL == tt.target()) {
+                    if (nullptr == tt.target()) {
                         continue;
                     }
                     GrPrimitiveEdgeType et = (GrPrimitiveEdgeType)edgeType;
diff --git a/gm/bigrrectaaeffect.cpp b/gm/bigrrectaaeffect.cpp
index f19b57ce45..3facc8c47c 100644
--- a/gm/bigrrectaaeffect.cpp
+++ b/gm/bigrrectaaeffect.cpp
@@ -32,7 +32,7 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        GrContext* context = rt ? rt->getContext() : NULL;
+        GrContext* context = rt ? rt->getContext() : nullptr;
         if (!context) {
             this->drawGpuOnlyMessage(canvas);
             return;
@@ -66,7 +66,7 @@ protected:
                     canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
                     GrTestTarget tt;
                     context->getTestTarget(&tt);
-                    if (NULL == tt.target()) {
+                    if (nullptr == tt.target()) {
                         SkDEBUGFAIL("Couldn't get Gr test target.");
                         return;
                     }
diff --git a/gm/bigtileimagefilter.cpp b/gm/bigtileimagefilter.cpp
index dbd41c2ebd..3c55b71410 100644
--- a/gm/bigtileimagefilter.cpp
+++ b/gm/bigtileimagefilter.cpp
@@ -74,7 +74,7 @@ protected:
             SkAutoTUnref<SkTileImageFilter> tif2(SkTileImageFilter::Create(
                             SkRect::MakeWH(SkIntToScalar(kBitmapSize), SkIntToScalar(kBitmapSize)),
                             SkRect::MakeWH(SkIntToScalar(kBitmapSize), SkIntToScalar(kBitmapSize)),
-                            NULL));
+                            nullptr));
             p2.setImageFilter(tif2);
 
             canvas->translate(320, 320);
diff --git a/gm/bitmapfilters.cpp b/gm/bitmapfilters.cpp
index aeb88d6d22..b7273288ac 100644
--- a/gm/bitmapfilters.cpp
+++ b/gm/bitmapfilters.cpp
@@ -21,7 +21,7 @@ static void make_bm(SkBitmap* bm) {
 
     bm->allocPixels(SkImageInfo::Make(2, 2, kIndex_8_SkColorType,
                                       kPremul_SkAlphaType),
-                    NULL, ctable);
+                    nullptr, ctable);
     ctable->unref();
 
     *bm->getAddr8(0, 0) = 0;
diff --git a/gm/bitmaprect.cpp b/gm/bitmaprect.cpp
index cfceab5af9..077f0ee273 100644
--- a/gm/bitmaprect.cpp
+++ b/gm/bitmaprect.cpp
@@ -23,7 +23,7 @@ static void make_bitmap(SkBitmap* bitmap) {
     paint.setAntiAlias(true);
     const SkPoint pts[] = { { 0, 0 }, { 64, 64 } };
     const SkColor colors[] = { SK_ColorWHITE, SK_ColorBLUE };
-    paint.setShader(SkGradientShader::CreateLinear(pts, colors, NULL, 2,
+    paint.setShader(SkGradientShader::CreateLinear(pts, colors, nullptr, 2,
                                                    SkShader::kClamp_TileMode))->unref();
     canvas.drawCircle(32, 32, 32, paint);
 }
diff --git a/gm/bitmaprecttest.cpp b/gm/bitmaprecttest.cpp
index 878029a8dd..741cc9ddfd 100644
--- a/gm/bitmaprecttest.cpp
+++ b/gm/bitmaprecttest.cpp
@@ -38,7 +38,7 @@ static void test_bitmaprect(SkCanvas* canvas) {
     SkBitmap bm;
     make_bm(&bm);
 
-    canvas->drawBitmap(bm, 150, 45, NULL);
+    canvas->drawBitmap(bm, 150, 45, nullptr);
 
     SkScalar scale = 0.472560018f;
     canvas->save();
@@ -47,7 +47,7 @@ static void test_bitmaprect(SkCanvas* canvas) {
     canvas->restore();
 
     canvas->scale(-1, 1);
-    canvas->drawBitmap(bm, -310, 45, NULL);
+    canvas->drawBitmap(bm, -310, 45, nullptr);
 }
 
 class BitmapRectTestGM : public skiagm::GM {
diff --git a/gm/bitmapshader.cpp b/gm/bitmapshader.cpp
index 2b6906f381..5d7b35c2cd 100644
--- a/gm/bitmapshader.cpp
+++ b/gm/bitmapshader.cpp
@@ -84,7 +84,7 @@ protected:
             canvas->translate(0, 25);
 
             // clear the shader, colorized by a solid color with a bitmap mask
-            paint.setShader(NULL);
+            paint.setShader(nullptr);
             paint.setColor(SK_ColorGREEN);
             canvas->drawBitmap(fMask, 0, 0, &paint);
             canvas->drawBitmap(fMask, 30, 0, &paint);
diff --git a/gm/bitmapsource2.cpp b/gm/bitmapsource2.cpp
index 6c32f625d9..f65bafd2bc 100644
--- a/gm/bitmapsource2.cpp
+++ b/gm/bitmapsource2.cpp
@@ -66,7 +66,7 @@ protected:
         SkPaint p;
         p.setImageFilter(filter);
 
-        canvas->saveLayer(NULL, &p);
+        canvas->saveLayer(nullptr, &p);
         canvas->restore();
     }
 
diff --git a/gm/blend.cpp b/gm/blend.cpp
index a89ecfe46d..94dc4c7f75 100644
--- a/gm/blend.cpp
+++ b/gm/blend.cpp
@@ -21,14 +21,14 @@ DEF_SIMPLE_GM(blend, canvas, 300, 100) {
 
         p.setColor(SK_ColorRED);
         canvas->drawRect(SkRect::MakeXYWH(1,0,1,1), p);
-        canvas->saveLayer(NULL, NULL);
+        canvas->saveLayer(nullptr, nullptr);
             p.setColor(0xFC008000);
             canvas->drawRect(SkRect::MakeXYWH(1,0,1,1), p);
         canvas->restore();
 
         p.setColor(SK_ColorRED);
         canvas->drawRect(SkRect::MakeXYWH(2,0,1,1), p);
-        canvas->saveLayerAlpha(NULL, 0xFC);
+        canvas->saveLayerAlpha(nullptr, 0xFC);
             p.setColor(sk_tool_utils::color_to_565(0xFF008000));
             canvas->drawRect(SkRect::MakeXYWH(2,0,1,1), p);
         canvas->restore();
@@ -36,7 +36,7 @@ DEF_SIMPLE_GM(blend, canvas, 300, 100) {
 
     // Print out the colors in each block (if we're looking at 8888 raster).
     if (canvas->imageInfo().colorType() == kN32_SkColorType) {
-        if (const SkPMColor* px = (const SkPMColor*)canvas->peekPixels(NULL, NULL)) {
+        if (const SkPMColor* px = (const SkPMColor*)canvas->peekPixels(nullptr, nullptr)) {
             p.setColor(SK_ColorWHITE);
             for (int i = 0; i < 3; i++) {
                 SkPMColor c = px[i * 100];
diff --git a/gm/blurrect.cpp b/gm/blurrect.cpp
index 0726f2cd52..6b7354071b 100644
--- a/gm/blurrect.cpp
+++ b/gm/blurrect.cpp
@@ -235,7 +235,7 @@ protected:
                     canvas->save();
                     canvas->translate((SkScalar)cur_x, (SkScalar)cur_y);
                     canvas->translate(-(bm.width() - r.width())/2, -(bm.height()-r.height())/2);
-                    canvas->drawBitmap(bm, 0.f, 0.f, NULL);
+                    canvas->drawBitmap(bm, 0.f, 0.f, nullptr);
                     canvas->restore();
 
                     cur_x += bm.width() + fPadding;
@@ -313,7 +313,7 @@ protected:
         center_x = (canvas_size.fWidth - mask.fBounds.width())/2;
         center_y = (canvas_size.fHeight - mask.fBounds.height())/2;
 
-        canvas->drawBitmap(bm, SkIntToScalar(center_x), SkIntToScalar(center_y), NULL);
+        canvas->drawBitmap(bm, SkIntToScalar(center_x), SkIntToScalar(center_y), nullptr);
     }
 
 private:
diff --git a/gm/blurs.cpp b/gm/blurs.cpp
index 8f95f007fa..d52a656963 100644
--- a/gm/blurs.cpp
+++ b/gm/blurs.cpp
@@ -56,7 +56,7 @@ protected:
                                            flags);
                     paint.setMaskFilter(mf)->unref();
                 } else {
-                    paint.setMaskFilter(NULL);
+                    paint.setMaskFilter(nullptr);
                 }
                 canvas->drawCircle(SkIntToScalar(200 + gRecs[i].fCx*100),
                                    SkIntToScalar(200 + gRecs[i].fCy*100),
@@ -75,7 +75,7 @@ protected:
                 canvas->drawText("Hamburgefons Style", 18, x, y, paint);
                 canvas->drawText("Hamburgefons Style", 18,
                                  x, y + SkIntToScalar(50), paint);
-                paint.setMaskFilter(NULL);
+                paint.setMaskFilter(nullptr);
                 paint.setColor(SK_ColorWHITE);
                 x -= SkIntToScalar(2);
                 y -= SkIntToScalar(2);
diff --git a/gm/colorcube.cpp b/gm/colorcube.cpp
index 931dcfaf51..18de813134 100644
--- a/gm/colorcube.cpp
+++ b/gm/colorcube.cpp
@@ -20,18 +20,18 @@ static SkShader* MakeLinear() {
         };
     static const SkColor colors[] = { SK_ColorYELLOW, SK_ColorBLUE };
     return SkGradientShader::CreateLinear(
-        pts, colors, NULL, 2, SkShader::kRepeat_TileMode, 0, &SkMatrix::I());
+        pts, colors, nullptr, 2, SkShader::kRepeat_TileMode, 0, &SkMatrix::I());
 }
 
 class ColorCubeGM : public GM {
 public:
     ColorCubeGM()
     : fInitialized(false)
-    , f3DLut4(NULL)
-    , f3DLut8(NULL)
-    , f3DLut16(NULL)
-    , f3DLut32(NULL)
-    , f3DLut64(NULL)
+    , f3DLut4(nullptr)
+    , f3DLut8(nullptr)
+    , f3DLut16(nullptr)
+    , f3DLut32(nullptr)
+    , f3DLut64(nullptr)
     {
         this->setBGColor(0xFF000000);
     }
diff --git a/gm/coloremoji.cpp b/gm/coloremoji.cpp
index 8ef335a158..6dddc0fdc6 100644
--- a/gm/coloremoji.cpp
+++ b/gm/coloremoji.cpp
@@ -27,7 +27,7 @@ static SkShader* MakeLinear() {
                                           SK_ARRAY_COUNT(kColors), SkShader::kClamp_TileMode);
 }
 
-static SkImageFilter* make_grayscale(SkImageFilter* input = NULL) {
+static SkImageFilter* make_grayscale(SkImageFilter* input = nullptr) {
     SkScalar matrix[20];
     memset(matrix, 0, 20 * sizeof(SkScalar));
     matrix[0] = matrix[5] = matrix[10] = 0.2126f;
@@ -38,7 +38,7 @@ static SkImageFilter* make_grayscale(SkImageFilter* input = NULL) {
     return SkColorFilterImageFilter::Create(filter, input);
 }
 
-static SkImageFilter* make_blur(float amount, SkImageFilter* input = NULL) {
+static SkImageFilter* make_blur(float amount, SkImageFilter* input = nullptr) {
     return SkBlurImageFilter::Create(amount, amount, input);
 }
 
@@ -98,14 +98,14 @@ protected:
                     }
 
                     if (SkToBool(makeBlur) && SkToBool(makeGray)) {
-                        SkAutoTUnref<SkImageFilter> grayScale(make_grayscale(NULL));
+                        SkAutoTUnref<SkImageFilter> grayScale(make_grayscale(nullptr));
                         SkAutoTUnref<SkImageFilter> blur(make_blur(3.0f, grayScale));
                         shaderPaint.setImageFilter(blur);
                     } else if (SkToBool(makeBlur)) {
-                        SkAutoTUnref<SkImageFilter> blur(make_blur(3.0f, NULL));
+                        SkAutoTUnref<SkImageFilter> blur(make_blur(3.0f, nullptr));
                         shaderPaint.setImageFilter(blur);
                     } else if (SkToBool(makeGray)) {
-                        SkAutoTUnref<SkImageFilter> grayScale(make_grayscale(NULL));
+                        SkAutoTUnref<SkImageFilter> grayScale(make_grayscale(nullptr));
                         shaderPaint.setImageFilter(grayScale);
                     }
                     shaderPaint.setTextSize(30);
diff --git a/gm/colorfilterimagefilter.cpp b/gm/colorfilterimagefilter.cpp
index 500450f61b..4f5a768d57 100644
--- a/gm/colorfilterimagefilter.cpp
+++ b/gm/colorfilterimagefilter.cpp
@@ -18,11 +18,11 @@
 #define FILTER_HEIGHT   SkIntToScalar(30)
 #define MARGIN          SkIntToScalar(10)
 
-static SkImageFilter* make_blur(float amount, SkImageFilter* input = NULL) {
+static SkImageFilter* make_blur(float amount, SkImageFilter* input = nullptr) {
     return SkBlurImageFilter::Create(amount, amount, input);
 }
 
-static SkImageFilter* make_brightness(float amount, SkImageFilter* input = NULL) {
+static SkImageFilter* make_brightness(float amount, SkImageFilter* input = nullptr) {
     SkScalar amount255 = SkScalarMul(amount, SkIntToScalar(255));
     SkScalar matrix[20] = { 1, 0, 0, 0, amount255,
                             0, 1, 0, 0, amount255,
@@ -32,7 +32,7 @@ static SkImageFilter* make_brightness(float amount, SkImageFilter* input = NULL)
     return SkColorFilterImageFilter::Create(filter, input);
 }
 
-static SkImageFilter* make_grayscale(SkImageFilter* input = NULL) {
+static SkImageFilter* make_grayscale(SkImageFilter* input = nullptr) {
     SkScalar matrix[20];
     memset(matrix, 0, 20 * sizeof(SkScalar));
     matrix[0] = matrix[5] = matrix[10] = 0.2126f;
@@ -43,7 +43,7 @@ static SkImageFilter* make_grayscale(SkImageFilter* input = NULL) {
     return SkColorFilterImageFilter::Create(filter, input);
 }
 
-static SkImageFilter* make_mode_blue(SkImageFilter* input = NULL) {
+static SkImageFilter* make_mode_blue(SkImageFilter* input = nullptr) {
     SkAutoTUnref<SkColorFilter> filter(
         SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrc_Mode));
     return SkColorFilterImageFilter::Create(filter, input);
diff --git a/gm/colorfilters.cpp b/gm/colorfilters.cpp
index 73ca7f318d..2d220d2c1d 100644
--- a/gm/colorfilters.cpp
+++ b/gm/colorfilters.cpp
@@ -20,14 +20,14 @@ static SkShader* make_shader(const SkRect& bounds) {
         SK_ColorCYAN, SK_ColorMAGENTA, SK_ColorYELLOW,
     };
     return SkGradientShader::CreateLinear(pts,
-                                          colors, NULL, SK_ARRAY_COUNT(colors),
+                                          colors, nullptr, SK_ARRAY_COUNT(colors),
                                           SkShader::kClamp_TileMode);
 }
 
 typedef void (*InstallPaint)(SkPaint*, uint32_t, uint32_t);
 
 static void install_nothing(SkPaint* paint, uint32_t, uint32_t) {
-    paint->setColorFilter(NULL);
+    paint->setColorFilter(nullptr);
 }
 
 static void install_lighting(SkPaint* paint, uint32_t mul, uint32_t add) {
diff --git a/gm/colormatrix.cpp b/gm/colormatrix.cpp
index a80f8cb581..b466188c6a 100644
--- a/gm/colormatrix.cpp
+++ b/gm/colormatrix.cpp
@@ -67,7 +67,7 @@ protected:
         SkPoint pts[] = {{0, 0}, {SkIntToScalar(width), SkIntToScalar(height)}};
         SkColor colors[] = {0x00000000, 0xFFFFFFFF};
         SkPaint paint;
-        paint.setShader(SkGradientShader::CreateLinear(pts, colors, NULL, 2,
+        paint.setShader(SkGradientShader::CreateLinear(pts, colors, nullptr, 2,
                                                        SkShader::kClamp_TileMode))->unref();
         canvas.drawRect(SkRect::MakeWH(SkIntToScalar(width), SkIntToScalar(height)), paint);
         return SkImage::NewFromBitmap(bm);
diff --git a/gm/colortype.cpp b/gm/colortype.cpp
index 4d8c9d6056..76b13817a9 100644
--- a/gm/colortype.cpp
+++ b/gm/colortype.cpp
@@ -13,7 +13,7 @@
 class ColorTypeGM : public skiagm::GM {
 public:
     ColorTypeGM()
-        : fColorType(NULL) {
+        : fColorType(nullptr) {
     }
 
     virtual ~ColorTypeGM() {
@@ -28,7 +28,7 @@ protected:
         };
         SkMatrix local;
         local.setRotate(180);
-        SkShader* s = SkGradientShader::CreateSweep(0,0, colors, NULL,
+        SkShader* s = SkGradientShader::CreateSweep(0,0, colors, nullptr,
                                                     SK_ARRAY_COUNT(colors), 0, &local);
 
         SkPaint paint;
@@ -37,7 +37,7 @@ protected:
 
         SkTypeface* orig = sk_tool_utils::create_portable_typeface("serif",
                                                             SkTypeface::kBold);
-        if (NULL == orig) {
+        if (nullptr == orig) {
             orig = SkTypeface::RefDefault();
         }
         fColorType = new SkGTypeface(orig, paint);
@@ -59,7 +59,7 @@ protected:
 
         for (SkScalar size = 10; size <= 100; size += 10) {
             paint.setTextSize(size);
-            canvas->translate(0, paint.getFontMetrics(NULL));
+            canvas->translate(0, paint.getFontMetrics(nullptr));
             canvas->drawText("Hamburgefons", 12, 10, 10, paint);
         }
     }
diff --git a/gm/colortypexfermode.cpp b/gm/colortypexfermode.cpp
index 2926523c27..55d7697e35 100644
--- a/gm/colortypexfermode.cpp
+++ b/gm/colortypexfermode.cpp
@@ -20,7 +20,7 @@ public:
     const static int W = 64;
     const static int H = 64;
     ColorTypeXfermodeGM()
-        : fColorType(NULL) {
+        : fColorType(nullptr) {
     }
 
     virtual ~ColorTypeXfermodeGM() {
@@ -35,7 +35,7 @@ protected:
         };
         SkMatrix local;
         local.setRotate(180);
-        SkShader* s = SkGradientShader::CreateSweep(0,0, colors, NULL,
+        SkShader* s = SkGradientShader::CreateSweep(0,0, colors, nullptr,
                                                     SK_ARRAY_COUNT(colors), 0, &local);
 
         SkPaint paint;
@@ -44,7 +44,7 @@ protected:
 
         SkTypeface* orig = sk_tool_utils::create_portable_typeface("serif",
                                                             SkTypeface::kBold);
-        if (NULL == orig) {
+        if (nullptr == orig) {
             orig = SkTypeface::RefDefault();
         }
         fColorType = new SkGTypeface(orig, paint);
@@ -138,7 +138,7 @@ protected:
 
             r.inset(-SK_ScalarHalf, -SK_ScalarHalf);
             p.setStyle(SkPaint::kStroke_Style);
-            p.setShader(NULL);
+            p.setShader(nullptr);
             canvas->drawRect(r, p);
 
             textP.setXfermode(mode);
diff --git a/gm/colorwheel.cpp b/gm/colorwheel.cpp
index dfa81ead70..efa3a6b0b4 100644
--- a/gm/colorwheel.cpp
+++ b/gm/colorwheel.cpp
@@ -40,7 +40,7 @@ DEF_SIMPLE_GM(colorwheel, canvas, 256, 256) {
 
 DEF_SIMPLE_GM(colorwheelnative, canvas, 128, 28) {
     SkPaint paint;
-    sk_tool_utils::set_portable_typeface(&paint, NULL, SkTypeface::kBold);
+    sk_tool_utils::set_portable_typeface(&paint, nullptr, SkTypeface::kBold);
     paint.setTextSize(18.0f);
 
     canvas->clear(sk_tool_utils::color_to_565(SK_ColorLTGRAY));
diff --git a/gm/complexclip.cpp b/gm/complexclip.cpp
index 74c877d8e6..bcbd7fd17a 100644
--- a/gm/complexclip.cpp
+++ b/gm/complexclip.cpp
@@ -115,7 +115,7 @@ protected:
             boundPaint.setColor(SK_ColorRED);
             boundPaint.setStyle(SkPaint::kStroke_Style);
             canvas->drawRect(bounds, boundPaint);
-            canvas->saveLayer(&bounds, NULL);
+            canvas->saveLayer(&bounds, nullptr);
         }
 
         for (int invBits = 0; invBits < 4; ++invBits) {
diff --git a/gm/composeshader.cpp b/gm/composeshader.cpp
index 9d2103beb4..f5ab996f37 100644
--- a/gm/composeshader.cpp
+++ b/gm/composeshader.cpp
@@ -23,14 +23,14 @@ static SkShader* make_shader(SkXfermode::Mode mode) {
     pts[1].set(SkIntToScalar(100), 0);
     colors[0] = SK_ColorRED;
     colors[1] = SK_ColorBLUE;
-    SkAutoTUnref<SkShader> shaderA(SkGradientShader::CreateLinear(pts, colors, NULL, 2,
+    SkAutoTUnref<SkShader> shaderA(SkGradientShader::CreateLinear(pts, colors, nullptr, 2,
                                                                   SkShader::kClamp_TileMode));
 
     pts[0].set(0, 0);
     pts[1].set(0, SkIntToScalar(100));
     colors[0] = SK_ColorBLACK;
     colors[1] = SkColorSetARGB(0x80, 0, 0, 0);
-    SkAutoTUnref<SkShader> shaderB(SkGradientShader::CreateLinear(pts, colors, NULL, 2,
+    SkAutoTUnref<SkShader> shaderB(SkGradientShader::CreateLinear(pts, colors, nullptr, 2,
                                                                   SkShader::kClamp_TileMode));
 
     SkAutoTUnref<SkXfermode> xfer(SkXfermode::Create(mode));
@@ -102,7 +102,7 @@ protected:
             canvas->save();
             for (int alpha = 0xFF; alpha > 0; alpha -= 0x28) {
                 paint.setAlpha(0xFF);
-                paint.setShader(NULL);
+                paint.setShader(nullptr);
                 canvas->drawRect(r, paint);
 
                 paint.setAlpha(alpha);
diff --git a/gm/constcolorprocessor.cpp b/gm/constcolorprocessor.cpp
index f5d7853ba7..3d2e5865d8 100644
--- a/gm/constcolorprocessor.cpp
+++ b/gm/constcolorprocessor.cpp
@@ -40,17 +40,17 @@ protected:
     void onOnceBeforeDraw() override {
         SkColor colors[] = { 0xFFFF0000, 0x2000FF00, 0xFF0000FF};
         SkPoint pts[] = { SkPoint::Make(0, 0), SkPoint::Make(kRectSize, kRectSize) };
-        fShader.reset(SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
+        fShader.reset(SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
                        SkShader::kClamp_TileMode));
     }
 
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        if (NULL == rt) {
+        if (nullptr == rt) {
             return;
         }
         GrContext* context = rt->getContext();
-        if (NULL == context) {
+        if (nullptr == context) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
@@ -92,7 +92,7 @@ protected:
 
                     GrTestTarget tt;
                     context->getTestTarget(&tt);
-                    if (NULL == tt.target()) {
+                    if (nullptr == tt.target()) {
                         SkDEBUGFAIL("Couldn't get Gr test target.");
                         return;
                     }
diff --git a/gm/convex_all_line_paths.cpp b/gm/convex_all_line_paths.cpp
index 6c494cdfc4..3eae959a65 100644
--- a/gm/convex_all_line_paths.cpp
+++ b/gm/convex_all_line_paths.cpp
@@ -165,7 +165,7 @@ protected:
         };
         static_assert(SK_ARRAY_COUNT(gSizes) == SK_ARRAY_COUNT(gPoints), "array_mismatch");
 
-        SkAutoTDeleteArray<SkPoint> data(NULL);
+        SkAutoTDeleteArray<SkPoint> data(nullptr);
         const SkPoint* points;
         int numPts;
         if (index < (int) SK_ARRAY_COUNT(gPoints)) {
diff --git a/gm/convexpolyclip.cpp b/gm/convexpolyclip.cpp
index 2aa05a83d2..fbfd1670d5 100644
--- a/gm/convexpolyclip.cpp
+++ b/gm/convexpolyclip.cpp
@@ -169,7 +169,7 @@ protected:
                         clip->getBounds(&bounds);
                         bounds.outset(2, 2);
                         bounds.offset(x, y);
-                        canvas->saveLayer(&bounds, NULL);
+                        canvas->saveLayer(&bounds, nullptr);
                     } else {
                         canvas->save();
                     }
@@ -192,7 +192,7 @@ protected:
                         clip->getBounds(&bounds);
                         bounds.outset(2, 2);
                         bounds.offset(x, y);
-                        canvas->saveLayer(&bounds, NULL);
+                        canvas->saveLayer(&bounds, nullptr);
                     } else {
                         canvas->save();
                     }
diff --git a/gm/convexpolyeffect.cpp b/gm/convexpolyeffect.cpp
index 95482f74be..b6a05cc6be 100644
--- a/gm/convexpolyeffect.cpp
+++ b/gm/convexpolyeffect.cpp
@@ -151,12 +151,12 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         using namespace GrDefaultGeoProcFactory;
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        if (NULL == rt) {
+        if (nullptr == rt) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
         GrContext* context = rt->getContext();
-        if (NULL == context) {
+        if (nullptr == context) {
             return;
         }
 
@@ -176,7 +176,7 @@ protected:
             for (int et = 0; et < kGrProcessorEdgeTypeCnt; ++et) {
                 GrTestTarget tt;
                 context->getTestTarget(&tt);
-                if (NULL == tt.target()) {
+                if (nullptr == tt.target()) {
                     SkDEBUGFAIL("Couldn't get Gr test target.");
                     return;
                 }
@@ -227,7 +227,7 @@ protected:
             for (int et = 0; et < kGrProcessorEdgeTypeCnt; ++et) {
                 GrTestTarget tt;
                 context->getTestTarget(&tt);
-                if (NULL == tt.target()) {
+                if (nullptr == tt.target()) {
                     SkDEBUGFAIL("Couldn't get Gr test target.");
                     return;
                 }
diff --git a/gm/dashcubics.cpp b/gm/dashcubics.cpp
index 246d0548ca..ecbe41537b 100644
--- a/gm/dashcubics.cpp
+++ b/gm/dashcubics.cpp
@@ -45,7 +45,7 @@ protected:
         canvas->drawPath(path, paint);
 
         paint.setColor(SK_ColorGREEN);
-        paint.setPathEffect(NULL);
+        paint.setPathEffect(nullptr);
         paint.setStrokeWidth(0);
         canvas->drawPath(path, paint);
     }
diff --git a/gm/dcshader.cpp b/gm/dcshader.cpp
index e0cb2d714f..3eee43d147 100644
--- a/gm/dcshader.cpp
+++ b/gm/dcshader.cpp
@@ -226,7 +226,7 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         // This GM exists to test a specific feature of the GPU backend. It does not work with the
         // sw rasterizer, tile modes, etc.
-        if (NULL == canvas->getGrContext()) {
+        if (nullptr == canvas->getGrContext()) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
diff --git a/gm/dftext.cpp b/gm/dftext.cpp
index f6bc0b2b9c..c66e03fdc8 100644
--- a/gm/dftext.cpp
+++ b/gm/dftext.cpp
@@ -81,7 +81,7 @@ protected:
             canvas->scale(scales[i], scales[i]);
             paint.setTextSize(textSizes[i]);
             canvas->drawText(text, textLen, 0, 0, paint);
-            y += paint.getFontMetrics(NULL)*scales[i];
+            y += paint.getFontMetrics(nullptr)*scales[i];
         }
 
         // check rotation
@@ -95,7 +95,7 @@ protected:
             for (int ps = 6; ps <= 32; ps += 3) {
                 paint.setTextSize(SkIntToScalar(ps));
                 canvas->drawText(text, textLen, rotX, rotY, paint);
-                rotY += paint.getFontMetrics(NULL);
+                rotY += paint.getFontMetrics(nullptr);
             }
         }
 
@@ -111,7 +111,7 @@ protected:
             canvas->scale(scaleFactor, scaleFactor);
             paint.setTextSize(textSizes[i]);
             canvas->drawText(text, textLen, 0, 0, paint);
-            y += paint.getFontMetrics(NULL)*scaleFactor;
+            y += paint.getFontMetrics(nullptr)*scaleFactor;
         }
 
         // check pos text
@@ -156,7 +156,7 @@ protected:
             paint.setColor(fg[i]);
 
             canvas->drawText(text, textLen, x, y, paint);
-            y += paint.getFontMetrics(NULL);
+            y += paint.getFontMetrics(nullptr);
         }
 
         paint.setColor(0xFF181C18);
@@ -170,7 +170,7 @@ protected:
             paint.setColor(fg[i]);
 
             canvas->drawText(text, textLen, x, y, paint);
-            y += paint.getFontMetrics(NULL);
+            y += paint.getFontMetrics(nullptr);
         }
 
         // check skew
@@ -202,7 +202,7 @@ protected:
             // since we prepended this matrix already, we blit using identity
             inputCanvas->resetMatrix();
             SkImage* image = surface->newImageSnapshot();
-            inputCanvas->drawImage(image, 0, 0, NULL);
+            inputCanvas->drawImage(image, 0, 0, nullptr);
             image->unref();
         }
 #endif
diff --git a/gm/discard.cpp b/gm/discard.cpp
index 93da1ab52a..85ef382ae7 100644
--- a/gm/discard.cpp
+++ b/gm/discard.cpp
@@ -37,7 +37,7 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         GrContext* context = canvas->getGrContext();
-        if (NULL == context) {
+        if (nullptr == context) {
             return;
         }
 
@@ -47,7 +47,7 @@ protected:
         SkImageInfo info = SkImageInfo::MakeN32Premul(size);
         SkSurface* surface = SkSurface::NewRenderTarget(context, SkSurface::kNo_Budgeted, info);
 
-        if (NULL == surface) {
+        if (nullptr == surface) {
             return;
         }
 
@@ -73,7 +73,7 @@ protected:
                       surface->getCanvas()->drawPaint(paint);
                       break;
               }
-              surface->draw(canvas, 10.f*x, 10.f*y, NULL);
+              surface->draw(canvas, 10.f*x, 10.f*y, nullptr);
             }
         }
 
diff --git a/gm/displacement.cpp b/gm/displacement.cpp
index 4450fe2eec..353d14ecd8 100644
--- a/gm/displacement.cpp
+++ b/gm/displacement.cpp
@@ -118,53 +118,53 @@ protected:
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kR_ChannelSelectorType,
             SkDisplacementMapEffect::kG_ChannelSelectorType,
-            0.0f, displ, NULL, &cropRect))->unref();
+            0.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 0, 200, paint);
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kB_ChannelSelectorType,
             SkDisplacementMapEffect::kA_ChannelSelectorType,
-            16.0f, displ, NULL, &cropRect))->unref();
+            16.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 100, 200, paint);
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kR_ChannelSelectorType,
             SkDisplacementMapEffect::kB_ChannelSelectorType,
-            32.0f, displ, NULL, &cropRect))->unref();
+            32.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 200, 200, paint);
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kG_ChannelSelectorType,
             SkDisplacementMapEffect::kA_ChannelSelectorType,
-            48.0f, displ, NULL, &cropRect))->unref();
+            48.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 300, 200, paint);
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kR_ChannelSelectorType,
             SkDisplacementMapEffect::kA_ChannelSelectorType,
-            64.0f, displ, NULL, &cropRect))->unref();
+            64.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 400, 200, paint);
 
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kR_ChannelSelectorType,
             SkDisplacementMapEffect::kG_ChannelSelectorType,
-            40.0f, displ, NULL, &cropRect))->unref();
+            40.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 0, 300, paint);
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kB_ChannelSelectorType,
             SkDisplacementMapEffect::kA_ChannelSelectorType,
-            40.0f, displ, NULL, &cropRect))->unref();
+            40.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 100, 300, paint);
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kR_ChannelSelectorType,
             SkDisplacementMapEffect::kB_ChannelSelectorType,
-            40.0f, displ, NULL, &cropRect))->unref();
+            40.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 200, 300, paint);
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kG_ChannelSelectorType,
             SkDisplacementMapEffect::kA_ChannelSelectorType,
-            40.0f, displ, NULL, &cropRect))->unref();
+            40.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 300, 300, paint);
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kR_ChannelSelectorType,
             SkDisplacementMapEffect::kA_ChannelSelectorType,
-            40.0f, displ, NULL, &cropRect))->unref();
+            40.0f, displ, nullptr, &cropRect))->unref();
         drawClippedBitmap(canvas, 400, 300, paint);
 
         // Tests for images of different sizes
@@ -199,7 +199,7 @@ protected:
         paint.setImageFilter(SkDisplacementMapEffect::Create(
             SkDisplacementMapEffect::kG_ChannelSelectorType,
             SkDisplacementMapEffect::kA_ChannelSelectorType,
-            40.0f, NULL))->unref();
+            40.0f, nullptr))->unref();
         drawClippedBitmap(canvas, 400, 400, paint);
     }
 
diff --git a/gm/distantclip.cpp b/gm/distantclip.cpp
index 54938b0d13..dbfe9160a8 100644
--- a/gm/distantclip.cpp
+++ b/gm/distantclip.cpp
@@ -34,7 +34,7 @@ protected:
         // We record a picture of huge vertical extents in which we clear the canvas to red, create
         // a 'extents' by 'extents' round rect clip at a vertical offset of 'offset', then draw
         // green into that.
-        SkCanvas* rec = recorder.beginRecording(kExtents, kOffset + kExtents, NULL, 0);
+        SkCanvas* rec = recorder.beginRecording(kExtents, kOffset + kExtents, nullptr, 0);
         rec->drawColor(SK_ColorRED);
         rec->save();
         SkRect r = SkRect::MakeXYWH(-kExtents, kOffset - kExtents, 2 * kExtents, 2 * kExtents);
@@ -48,7 +48,7 @@ protected:
         // Next we play that picture into another picture of the same size.
         pict->playback(recorder.beginRecording(pict->cullRect().width(), 
                                                pict->cullRect().height(), 
-                                               NULL, 0));
+                                               nullptr, 0));
         SkAutoTUnref<SkPicture> pict2(recorder.endRecording());
 
         // Finally we play the part of that second picture that should be green into the canvas.
diff --git a/gm/downsamplebitmap.cpp b/gm/downsamplebitmap.cpp
index 5732378703..d7a8b35927 100644
--- a/gm/downsamplebitmap.cpp
+++ b/gm/downsamplebitmap.cpp
@@ -171,7 +171,7 @@ class DownsampleBitmapImageGM: public DownsampleBitmapGM {
       int fSize;
 
       void make_bitmap() override {
-          SkImageDecoder* codec = NULL;
+          SkImageDecoder* codec = nullptr;
           SkString resourcePath = GetResourcePath(fFilename.c_str());
           SkFILEStream stream(resourcePath.c_str());
           if (stream.isValid()) {
@@ -219,20 +219,20 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         SkScalar x = 4;
         SkScalar y = 4;
-        canvas->drawBitmap(fBM, x, y, NULL);
+        canvas->drawBitmap(fBM, x, y, nullptr);
         y += fBM.height() + 4;
 
-        SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(fBM, NULL));
+        SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(fBM, nullptr));
 
         SkMipMap::Level level;
         SkScalar scale = 0.5f;
         while (mm->extractLevel(scale, &level)) {
             SkImageInfo info = SkImageInfo::MakeN32Premul(level.fWidth, level.fHeight);
             SkBitmap bm;
-            bm.installPixels(info, level.fPixels, level.fRowBytes, NULL,
+            bm.installPixels(info, level.fPixels, level.fRowBytes, nullptr,
                              &release_mipmap, (void*)(SkRef(mm.get())));
             bm.setImmutable();
-            canvas->drawBitmap(bm, x, y, NULL);
+            canvas->drawBitmap(bm, x, y, nullptr);
             y += bm.height() + 4;
             scale /= 2;
             if (info.width() == 1 || info.height() == 1) {
diff --git a/gm/drawatlas.cpp b/gm/drawatlas.cpp
index 89bd49c0a2..858e4bf056 100644
--- a/gm/drawatlas.cpp
+++ b/gm/drawatlas.cpp
@@ -14,7 +14,7 @@ class DrawAtlasGM : public skiagm::GM {
     static SkImage* MakeAtlas(SkCanvas* caller, const SkRect& target) {
         SkImageInfo info = SkImageInfo::MakeN32Premul(100, 100);
         SkAutoTUnref<SkSurface> surface(caller->newSurface(info));
-        if (NULL == surface) {
+        if (nullptr == surface) {
             surface.reset(SkSurface::NewRaster(info));
         }
         SkCanvas* canvas = surface->getCanvas();
@@ -28,7 +28,7 @@ class DrawAtlasGM : public skiagm::GM {
         r.inset(-1, -1);
         // zero out a place (with a 1-pixel border) to land our drawing.
         canvas->drawRect(r, paint);
-        paint.setXfermode(NULL);
+        paint.setXfermode(nullptr);
         paint.setColor(SK_ColorBLUE);
         paint.setAntiAlias(true);
         canvas->drawOval(target, paint);
@@ -52,7 +52,7 @@ protected:
     
     void onDraw(SkCanvas* canvas) override {
         const SkRect target = { 50, 50, 80, 90 };
-        if (NULL == fAtlas) {
+        if (nullptr == fAtlas) {
             fAtlas.reset(MakeAtlas(canvas, target));
         }
 
@@ -91,9 +91,9 @@ protected:
         paint.setFilterQuality(kLow_SkFilterQuality);
         paint.setAntiAlias(true);
 
-        canvas->drawAtlas(fAtlas, xform, tex, N, NULL, &paint);
+        canvas->drawAtlas(fAtlas, xform, tex, N, nullptr, &paint);
         canvas->translate(0, 100);
-        canvas->drawAtlas(fAtlas, xform, tex, colors, N, SkXfermode::kSrcIn_Mode, NULL, &paint);
+        canvas->drawAtlas(fAtlas, xform, tex, colors, N, SkXfermode::kSrcIn_Mode, nullptr, &paint);
     }
     
 private:
diff --git a/gm/drawatlascolor.cpp b/gm/drawatlascolor.cpp
index a04822f033..b5f9d7a285 100644
--- a/gm/drawatlascolor.cpp
+++ b/gm/drawatlascolor.cpp
@@ -20,7 +20,7 @@ static SkImage* make_atlas(SkCanvas* caller, int atlasSize) {
 
     SkImageInfo info = SkImageInfo::MakeN32Premul(atlasSize, atlasSize);
     SkAutoTUnref<SkSurface> surface(caller->newSurface(info));
-    if (NULL == surface) {
+    if (nullptr == surface) {
         surface.reset(SkSurface::NewRaster(info));
     }
     SkCanvas* canvas = surface->getCanvas();
@@ -72,7 +72,7 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         const SkRect target = SkRect::MakeWH(SkIntToScalar(kAtlasSize), SkIntToScalar(kAtlasSize));
 
-        if (NULL == fAtlas) {
+        if (nullptr == fAtlas) {
             fAtlas.reset(make_atlas(canvas, kAtlasSize));
         }
 
@@ -138,7 +138,7 @@ protected:
         SkPaint textP;
         textP.setTextSize(SkIntToScalar(kTextPad));
         textP.setAntiAlias(true);
-        sk_tool_utils::set_portable_typeface(&textP, NULL);
+        sk_tool_utils::set_portable_typeface(&textP, nullptr);
 
         for (int i = 0; i < numModes; ++i) {
             canvas->drawText(gModes[i].fLabel, strlen(gModes[i].fLabel),
@@ -152,11 +152,11 @@ protected:
                               SkIntToScalar(kTextPad+kPad));
             // w/o a paint
             canvas->drawAtlas(fAtlas, xforms, rects, quadColors, numColors, 
-                              gModes[i].fMode, NULL, NULL);
+                              gModes[i].fMode, nullptr, nullptr);
             canvas->translate(0.0f, numColors*(target.height()+kPad));
             // w a paint
             canvas->drawAtlas(fAtlas, xforms, rects, quadColors, numColors, 
-                              gModes[i].fMode, NULL, &paint);
+                              gModes[i].fMode, nullptr, &paint);
             canvas->restore();        
         }
     }
diff --git a/gm/drawbitmaprect.cpp b/gm/drawbitmaprect.cpp
index 2a41465a35..dd6d2b7a7d 100644
--- a/gm/drawbitmaprect.cpp
+++ b/gm/drawbitmaprect.cpp
@@ -81,12 +81,12 @@ static SkImage* makebm(SkBitmap* bm, int w, int h) {
 
 static void canvasproc(SkCanvas* canvas, SkImage*, const SkBitmap& bm, const SkIRect& srcR,
                        const SkRect& dstR) {
-    canvas->drawBitmapRect(bm, srcR, dstR, NULL);
+    canvas->drawBitmapRect(bm, srcR, dstR, nullptr);
 }
 
 static void imageproc(SkCanvas* canvas, SkImage* image, const SkBitmap&, const SkIRect& srcR,
                       const SkRect& dstR) {
-    canvas->drawImageRect(image, srcR, dstR, NULL);
+    canvas->drawImageRect(image, srcR, dstR, nullptr);
 }
 
 static void imagescaleproc(SkCanvas* canvas, SkImage* image, const SkBitmap&, const SkIRect& srcIR,
@@ -226,6 +226,6 @@ private:
     typedef skiagm::GM INHERITED;
 };
 
-DEF_GM( return new DrawBitmapRectGM(canvasproc, NULL); )
+DEF_GM( return new DrawBitmapRectGM(canvasproc, nullptr); )
 DEF_GM( return new DrawBitmapRectGM(imageproc, "-imagerect"); )
 DEF_GM( return new DrawBitmapRectGM(imagescaleproc, "-imagescale"); )
diff --git a/gm/drawfilter.cpp b/gm/drawfilter.cpp
index 8c29f07b02..b0a21e9a11 100644
--- a/gm/drawfilter.cpp
+++ b/gm/drawfilter.cpp
@@ -24,7 +24,7 @@ class TestFilter : public SkDrawFilter {
 public:
     bool filter(SkPaint* p, Type) override {
         p->setColor(SK_ColorRED);
-        p->setMaskFilter(NULL);
+        p->setMaskFilter(nullptr);
         return true;
     }
 };
@@ -53,7 +53,7 @@ protected:
         p.setColor(SK_ColorBLUE);
         p.setMaskFilter(fBlur.get());
         SkRect r = { 20, 20, 100, 100 };
-        canvas->setDrawFilter(NULL);
+        canvas->setDrawFilter(nullptr);
         canvas->drawRect(r, p);
         TestFilter redNoBlur;
         canvas->setDrawFilter(&redNoBlur);
@@ -61,7 +61,7 @@ protected:
         canvas->drawRect(r, p);
 
         // Must unset if the DrawFilter is from the stack to avoid refcount errors!
-        canvas->setDrawFilter(NULL);
+        canvas->setDrawFilter(nullptr);
     }
 
 private:
diff --git a/gm/drawlooper.cpp b/gm/drawlooper.cpp
index 624358f7eb..ffa7d6c91b 100644
--- a/gm/drawlooper.cpp
+++ b/gm/drawlooper.cpp
@@ -18,7 +18,7 @@
 
 class DrawLooperGM : public skiagm::GM {
 public:
-    DrawLooperGM() : fLooper(NULL) {
+    DrawLooperGM() : fLooper(nullptr) {
         this->setBGColor(sk_tool_utils::color_to_565(0xFFDDDDDD));
     }
 
diff --git a/gm/drawminibitmaprect.cpp b/gm/drawminibitmaprect.cpp
index 56f99082f4..85071c56c4 100644
--- a/gm/drawminibitmaprect.cpp
+++ b/gm/drawminibitmaprect.cpp
@@ -16,7 +16,7 @@
 static SkImage* makebm(SkCanvas* caller, int w, int h) {
     SkImageInfo info = SkImageInfo::MakeN32Premul(w, h);
     SkAutoTUnref<SkSurface> surface(caller->newSurface(info));
-    if (NULL == surface) {
+    if (nullptr == surface) {
         surface.reset(SkSurface::NewRaster(info));
     }
     SkCanvas* canvas = surface->getCanvas();
@@ -79,7 +79,7 @@ protected:
     SkISize onISize() override { return SkISize::Make(gSize, gSize); }
 
     void onDraw(SkCanvas* canvas) override {
-        if (NULL == fImage) {
+        if (nullptr == fImage) {
             fImage.reset(makebm(canvas, gSurfaceSize, gSurfaceSize));
         }
 
diff --git a/gm/dropshadowimagefilter.cpp b/gm/dropshadowimagefilter.cpp
index e06264c9da..1b6bca42d0 100644
--- a/gm/dropshadowimagefilter.cpp
+++ b/gm/dropshadowimagefilter.cpp
@@ -58,7 +58,7 @@ static void draw_bitmap(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     bm.allocN32Pixels(bounds.width(), bounds.height());
     bm.eraseColor(SK_ColorTRANSPARENT);
     SkCanvas c(bm);
-    draw_path(&c, r, NULL);
+    draw_path(&c, r, nullptr);
 
     paint.setImageFilter(imf);
     canvas->save();
@@ -125,7 +125,7 @@ protected:
                                           SkImageFilter::CropRect::kHasAll_CropEdge);
 
         SkImageFilter* filters[] = {
-            NULL,
+            nullptr,
             SkDropShadowImageFilter::Create(7.0f, 0.0f, 0.0f, 3.0f, SK_ColorBLUE,
                 SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode),
             SkDropShadowImageFilter::Create(0.0f, 7.0f, 3.0f, 0.0f, SK_ColorBLUE,
@@ -133,11 +133,11 @@ protected:
             SkDropShadowImageFilter::Create(7.0f, 7.0f, 3.0f, 3.0f, SK_ColorBLUE,
                 SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode),
             SkDropShadowImageFilter::Create(7.0f, 7.0f, 3.0f, 3.0f, SK_ColorBLUE,
-                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode, cfif, NULL),
+                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode, cfif, nullptr),
             SkDropShadowImageFilter::Create(7.0f, 7.0f, 3.0f, 3.0f, SK_ColorBLUE,
-                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode, NULL, &cropRect),
+                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode, nullptr, &cropRect),
             SkDropShadowImageFilter::Create(7.0f, 7.0f, 3.0f, 3.0f, SK_ColorBLUE,
-                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode, NULL, &bogusRect),
+                SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode, nullptr, &bogusRect),
             SkDropShadowImageFilter::Create(7.0f, 7.0f, 3.0f, 3.0f, SK_ColorBLUE,
                 SkDropShadowImageFilter::kDrawShadowOnly_ShadowMode),
         };
diff --git a/gm/etc1bitmap.cpp b/gm/etc1bitmap.cpp
index 363bd4419c..11a700eabc 100644
--- a/gm/etc1bitmap.cpp
+++ b/gm/etc1bitmap.cpp
@@ -98,7 +98,7 @@ protected:
         SkString filename = GetResourcePath("mandrill_128.");
         filename.append(this->fileExtension());
         SkAutoTUnref<SkData> fileData(SkData::NewFromFileName(filename.c_str()));
-        if (NULL == fileData) {
+        if (nullptr == fileData) {
             SkDebugf("Could not open the file. Did you forget to set the resourcePath?\n");
             return;
         }
@@ -182,7 +182,7 @@ protected:
         SkBitmap bm;
         SkString pkmFilename = GetResourcePath("mandrill_128.pkm");
         SkAutoDataUnref fileData(SkData::NewFromFileName(pkmFilename.c_str()));
-        if (NULL == fileData) {
+        if (nullptr == fileData) {
             SkDebugf("Could not open the file. Did you forget to set the resourcePath?\n");
             return;
         }
diff --git a/gm/factory.cpp b/gm/factory.cpp
index 0a938629b9..66cb65ee24 100644
--- a/gm/factory.cpp
+++ b/gm/factory.cpp
@@ -37,7 +37,7 @@ protected:
             SkAutoTUnref<SkDiscardableMemoryPool> pool(
                 SkDiscardableMemoryPool::Create(1));
             SkAssertResult(SkInstallDiscardablePixelRef(SkImageGenerator::NewFromEncoded(data),
-                                                        NULL, &fBitmap, pool));
+                                                        nullptr, &fBitmap, pool));
         }
     }
 
diff --git a/gm/fatpathfill.cpp b/gm/fatpathfill.cpp
index 711d713852..be5fbc4d56 100644
--- a/gm/fatpathfill.cpp
+++ b/gm/fatpathfill.cpp
@@ -36,7 +36,7 @@ static void draw_fatpath(SkCanvas* canvas, SkSurface* surface, const SkPath& pat
 
     surface->getCanvas()->clear(SK_ColorTRANSPARENT);
     surface->getCanvas()->drawPath(path, paint);
-    surface->draw(canvas, 0, 0, NULL);
+    surface->draw(canvas, 0, 0, nullptr);
 
     paint.setAntiAlias(true);
     paint.setColor(SK_ColorRED);
diff --git a/gm/filterbitmap.cpp b/gm/filterbitmap.cpp
index 1af16959c2..5c63910a78 100644
--- a/gm/filterbitmap.cpp
+++ b/gm/filterbitmap.cpp
@@ -196,7 +196,7 @@ protected:
       }
 
       void makeBitmap() override {
-          SkImageDecoder* codec = NULL;
+          SkImageDecoder* codec = nullptr;
           SkString resourcePath = GetResourcePath(fFilename.c_str());
           SkFILEStream stream(resourcePath.c_str());
           if (stream.isValid()) {
diff --git a/gm/filterfastbounds.cpp b/gm/filterfastbounds.cpp
index f6797db9f3..fe06ff1049 100644
--- a/gm/filterfastbounds.cpp
+++ b/gm/filterfastbounds.cpp
@@ -116,7 +116,7 @@ static void create_paints(SkImageFilter* source, SkTArray<SkPaint>* paints) {
             SkDropShadowImageFilter::Create(10.0f, 10.0f,
                                             3.0f, 3.0f,
                                             SK_ColorRED, kBoth,
-                                            source, NULL));
+                                            source, nullptr));
 
         add_paint(dsif, paints);
     }
@@ -127,7 +127,7 @@ static void create_paints(SkImageFilter* source, SkTArray<SkPaint>* paints) {
                                             3.0f, 3.0f,
                                             SK_ColorRED,
                                             SkDropShadowImageFilter::kDrawShadowOnly_ShadowMode,
-                                            source, NULL));
+                                            source, nullptr));
 
         add_paint(dsif, paints);
     }
@@ -231,7 +231,7 @@ protected:
         //-----------
         // Normal paints (no source)
         SkTArray<SkPaint> paints;
-        create_paints(NULL, &paints);
+        create_paints(nullptr, &paints);
 
         //-----------
         // Paints with a PictureImageFilter as a source
diff --git a/gm/filterindiabox.cpp b/gm/filterindiabox.cpp
index 8df39bcec7..c5d7166423 100644
--- a/gm/filterindiabox.cpp
+++ b/gm/filterindiabox.cpp
@@ -99,7 +99,7 @@ protected:
       }
 
       void makeBitmap() {
-          SkImageDecoder* codec = NULL;
+          SkImageDecoder* codec = nullptr;
           SkString resourcePath = GetResourcePath(fFilename.c_str());
           SkFILEStream stream(resourcePath.c_str());
           if (stream.isValid()) {
diff --git a/gm/fontcache.cpp b/gm/fontcache.cpp
index 77a4c86572..30f8892c78 100644
--- a/gm/fontcache.cpp
+++ b/gm/fontcache.cpp
@@ -21,8 +21,8 @@ static SkScalar draw_string(SkCanvas* canvas, const SkString& text, SkScalar x,
 class FontCacheGM : public skiagm::GM {
 public:
     FontCacheGM() {
-        fTypefaces[0] = NULL;
-        fTypefaces[1] = NULL;
+        fTypefaces[0] = nullptr;
+        fTypefaces[1] = nullptr;
     }
 
     virtual ~FontCacheGM() {
diff --git a/gm/fontmgr.cpp b/gm/fontmgr.cpp
index 9339115d0b..67be00d0ac 100644
--- a/gm/fontmgr.cpp
+++ b/gm/fontmgr.cpp
@@ -36,7 +36,7 @@ static SkScalar drawCharacter(SkCanvas* canvas, uint32_t character, SkScalar x,
     SkSafeUnref(paint.setTypeface(typeface));
     x = drawString(canvas, ch, x, y, paint) + 20;
 
-    if (NULL == typeface) {
+    if (nullptr == typeface) {
         return x;
     }
 
@@ -55,7 +55,7 @@ static const char* ja = "ja";
 
 class FontMgrGM : public skiagm::GM {
 public:
-    FontMgrGM(SkFontMgr* fontMgr = NULL) {
+    FontMgrGM(SkFontMgr* fontMgr = nullptr) {
         SkGraphics::SetFontCacheLimit(16 * 1024 * 1024);
 
         fName.set("fontmgr_iter");
@@ -92,7 +92,7 @@ protected:
         for (int i = 0; i < count; ++i) {
             SkString familyName;
             fm->getFamilyName(i, &familyName);
-            paint.setTypeface(NULL);
+            paint.setTypeface(nullptr);
             (void)drawString(canvas, familyName, 20, y, paint);
 
             SkScalar x = 220;
@@ -111,7 +111,7 @@ protected:
                 x = drawCharacter(canvas, 0x5203, x, y, paint, fm, familyName.c_str(), &zh, 1, fs);
                 x = drawCharacter(canvas, 0x5203, x, y, paint, fm, familyName.c_str(), &ja, 1, fs);
                 // check that emoji characters are found
-                x = drawCharacter(canvas, 0x1f601, x, y, paint, fm, familyName.c_str(), NULL,0, fs);
+                x = drawCharacter(canvas, 0x1f601, x, y, paint, fm, familyName.c_str(), nullptr,0, fs);
             }
             y += 24;
         }
@@ -199,7 +199,7 @@ protected:
                 break;
             }
         }
-        if (NULL == fset.get()) {
+        if (nullptr == fset.get()) {
             return;
         }
 
diff --git a/gm/fontscaler.cpp b/gm/fontscaler.cpp
index 6087478566..69cf346c4d 100644
--- a/gm/fontscaler.cpp
+++ b/gm/fontscaler.cpp
@@ -73,7 +73,7 @@ protected:
                 for (int ps = 6; ps <= 22; ps++) {
                     paint.setTextSize(SkIntToScalar(ps));
                     canvas->drawText(text, textLen, x, y, paint);
-                    y += paint.getFontMetrics(NULL);
+                    y += paint.getFontMetrics(nullptr);
                 }
             }
             canvas->translate(0, SkIntToScalar(360));
diff --git a/gm/fontscalerdistortable.cpp b/gm/fontscalerdistortable.cpp
index 715f32169c..a207f967fd 100644
--- a/gm/fontscalerdistortable.cpp
+++ b/gm/fontscalerdistortable.cpp
@@ -75,7 +75,7 @@ protected:
                 for (int ps = 6; ps <= 22; ps++) {
                     paint.setTextSize(SkIntToScalar(ps));
                     canvas->drawText(text, textLen, x, y, paint);
-                    y += paint.getFontMetrics(NULL);
+                    y += paint.getFontMetrics(nullptr);
                 }
             }
             canvas->translate(0, SkIntToScalar(360));
diff --git a/gm/gammatext.cpp b/gm/gammatext.cpp
index a46f828784..63acb40c13 100644
--- a/gm/gammatext.cpp
+++ b/gm/gammatext.cpp
@@ -14,7 +14,7 @@
 static SkShader* make_heatGradient(const SkPoint pts[2]) {
     const SkColor bw[] = { SK_ColorBLACK, SK_ColorWHITE };
 
-    return SkGradientShader::CreateLinear(pts, bw, NULL,
+    return SkGradientShader::CreateLinear(pts, bw, nullptr,
                                           SK_ARRAY_COUNT(bw),
                                           SkShader::kClamp_TileMode);
 }
@@ -106,7 +106,7 @@ static SkShader* make_gradient(SkColor c) {
     SkColor colors[2];
     colors[0] = c;
     colors[1] = SkColorSetA(c, 0);
-    return SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
+    return SkGradientShader::CreateLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
 }
 
 static void set_face(SkPaint* paint) {
@@ -118,7 +118,7 @@ static void draw_pair(SkCanvas* canvas, SkPaint* paint, SkShader* shader) {
     const char text[] = "Now is the time for all good";
     const size_t len = strlen(text);
     
-    paint->setShader(NULL);
+    paint->setShader(nullptr);
     canvas->drawText(text, len, 10, 20, *paint);
     paint->setShader(SkShader::CreateColorShader(paint->getColor()))->unref();
     canvas->drawText(text, len, 10, 40, *paint);
@@ -134,7 +134,7 @@ public:
     GammaShaderTextGM() {
         const SkColor colors[] = { SK_ColorBLACK, SK_ColorRED, SK_ColorBLUE };
         for (size_t i = 0; i < SK_ARRAY_COUNT(fShaders); ++i) {
-            fShaders[i] = NULL;
+            fShaders[i] = nullptr;
             fColors[i] = colors[i];
         }
     }
diff --git a/gm/giantbitmap.cpp b/gm/giantbitmap.cpp
index e8bfad4990..571dbd8114 100644
--- a/gm/giantbitmap.cpp
+++ b/gm/giantbitmap.cpp
@@ -25,7 +25,7 @@ class GiantBitmapGM : public skiagm::GM {
     bool fDoRotate;
 
     const SkBitmap& getBitmap() {
-        if (NULL == fBM) {
+        if (nullptr == fBM) {
             fBM = new SkBitmap;
             fBM->allocN32Pixels(W, H);
             fBM->eraseColor(SK_ColorWHITE);
@@ -60,7 +60,7 @@ class GiantBitmapGM : public skiagm::GM {
     }
 
 public:
-    GiantBitmapGM(SkShader::TileMode mode, bool doFilter, bool doRotate) : fBM(NULL) {
+    GiantBitmapGM(SkShader::TileMode mode, bool doFilter, bool doRotate) : fBM(nullptr) {
         fMode = mode;
         fDoFilter = doFilter;
         fDoRotate = doRotate;
diff --git a/gm/glyph_pos.cpp b/gm/glyph_pos.cpp
index e57f5c6767..15229b8dab 100644
--- a/gm/glyph_pos.cpp
+++ b/gm/glyph_pos.cpp
@@ -138,7 +138,7 @@ protected:
 
         if (drawRef) {
             SkScalar widths[sizeof(kText) - 1];
-            paint.getTextWidths(kText, sizeof(kText) - 1, widths, NULL);
+            paint.getTextWidths(kText, sizeof(kText) - 1, widths, nullptr);
 
             paint.setStrokeWidth(0.0f);
             paint.setStyle(SkPaint::kStroke_Style);
diff --git a/gm/glyph_pos_align.cpp b/gm/glyph_pos_align.cpp
index e8528047aa..9add494ffd 100644
--- a/gm/glyph_pos_align.cpp
+++ b/gm/glyph_pos_align.cpp
@@ -36,7 +36,7 @@ protected:
         paint.setFakeBoldText(true);
         const SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
         const SkPoint pts[] = {{0, 0}, {kWidth, kHeight}};
-        SkAutoTUnref<SkShader> grad(SkGradientShader::CreateLinear(pts, colors, NULL,
+        SkAutoTUnref<SkShader> grad(SkGradientShader::CreateLinear(pts, colors, nullptr,
                                                                    SK_ARRAY_COUNT(colors),
                                                                    SkShader::kMirror_TileMode));
         paint.setShader(grad);
diff --git a/gm/gm_expectations.h b/gm/gm_expectations.h
index 029a533c62..6767b90f51 100644
--- a/gm/gm_expectations.h
+++ b/gm/gm_expectations.h
@@ -147,10 +147,10 @@ namespace skiagm {
          * If this Expectation is based on a single SkBitmap, return a
          * pointer to that SkBitmap. Otherwise (if the Expectation is
          * empty, or if it was based on a list of checksums rather
-         * than a single bitmap), returns NULL.
+         * than a single bitmap), returns nullptr.
          */
         const SkBitmap *asBitmap() const {
-            return (kUnknown_SkColorType == fBitmap.colorType()) ? NULL : &fBitmap;
+            return (kUnknown_SkColorType == fBitmap.colorType()) ? nullptr : &fBitmap;
         }
 
         /**
diff --git a/gm/gradientDirtyLaundry.cpp b/gm/gradientDirtyLaundry.cpp
index 2ba0963013..8ef5fc9229 100644
--- a/gm/gradientDirtyLaundry.cpp
+++ b/gm/gradientDirtyLaundry.cpp
@@ -30,9 +30,9 @@ static const SkColor gColors[] = {
 //static const SkScalar gPos[] = { SK_Scalar1*999/2000, SK_Scalar1*1001/2000 };
 
 static const GradData gGradData[] = {
-    { 40, gColors, NULL },
+    { 40, gColors, nullptr },
     //  { 2, gColors, gPos },
-    //  { 2, gCol2, NULL },
+    //  { 2, gCol2, nullptr },
 };
 
 static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
diff --git a/gm/gradient_matrix.cpp b/gm/gradient_matrix.cpp
index 10499ca986..77227599e6 100644
--- a/gm/gradient_matrix.cpp
+++ b/gm/gradient_matrix.cpp
@@ -62,7 +62,7 @@ static const SkScalar TESTGRID_Y = SkIntToScalar(200);
 static const int IMAGES_X = 4;             // number of images per row
 
 static SkShader* make_linear_gradient(const SkPoint pts[2], const SkMatrix& localMatrix) {
-    return SkGradientShader::CreateLinear(pts, gColors, NULL, SK_ARRAY_COUNT(gColors),
+    return SkGradientShader::CreateLinear(pts, gColors, nullptr, SK_ARRAY_COUNT(gColors),
                                           SkShader::kClamp_TileMode, 0, &localMatrix);
 }
 
@@ -71,7 +71,7 @@ static SkShader* make_radial_gradient(const SkPoint pts[2], const SkMatrix& loca
     center.set(SkScalarAve(pts[0].fX, pts[1].fX),
                SkScalarAve(pts[0].fY, pts[1].fY));
     float radius = (center - pts[0]).length();
-    return SkGradientShader::CreateRadial(center, radius, gColors, NULL, SK_ARRAY_COUNT(gColors),
+    return SkGradientShader::CreateRadial(center, radius, gColors, nullptr, SK_ARRAY_COUNT(gColors),
                                           SkShader::kClamp_TileMode, 0, &localMatrix);
 }
 
diff --git a/gm/gradients.cpp b/gm/gradients.cpp
index ea2b8eae6b..ee6380c7ca 100644
--- a/gm/gradients.cpp
+++ b/gm/gradients.cpp
@@ -31,10 +31,10 @@ static const SkColor  gColorClamp[] = {
 };
 
 static const GradData gGradData[] = {
-    { 2, gColors, NULL },
+    { 2, gColors, nullptr },
     { 2, gColors, gPos0 },
     { 2, gColors, gPos1 },
-    { 5, gColors, NULL },
+    { 5, gColors, nullptr },
     { 5, gColors, gPos2 },
     { 4, gColorClamp, gPosClamp }
 };
@@ -311,7 +311,7 @@ protected:
         canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
         SkShader* shader = SkGradientShader::CreateRadial(
             SkPoint(center),
-            SkIntToScalar(200), gColors, NULL, 5,
+            SkIntToScalar(200), gColors, nullptr, 5,
             SkShader::kClamp_TileMode);
         paint.setShader(shader);
         canvas->drawRect(r, paint);
@@ -401,18 +401,18 @@ protected:
         for (size_t i = 0; i < SK_ARRAY_COUNT(flags); i++) {
             SkAutoTUnref<SkShader> sweep(
                     SkGradientShader::CreateSweep(cx, cy, sweep_colors,
-                                                  NULL, SK_ARRAY_COUNT(sweep_colors),
-                                                  flags[i], NULL));
+                                                  nullptr, SK_ARRAY_COUNT(sweep_colors),
+                                                  flags[i], nullptr));
             SkAutoTUnref<SkShader> radial1(
                     SkGradientShader::CreateRadial(center, radius, colors1,
-                                                   NULL, SK_ARRAY_COUNT(colors1),
+                                                   nullptr, SK_ARRAY_COUNT(colors1),
                                                    SkShader::kClamp_TileMode,
-                                                   flags[i], NULL));
+                                                   flags[i], nullptr));
             SkAutoTUnref<SkShader> radial2(
                     SkGradientShader::CreateRadial(center, radius, colors2,
-                                                   NULL, SK_ARRAY_COUNT(colors2),
+                                                   nullptr, SK_ARRAY_COUNT(colors2),
                                                    SkShader::kClamp_TileMode,
-                                                   flags[i], NULL));
+                                                   flags[i], nullptr));
             paint1.setShader(sweep);
             paint2.setShader(radial1);
             paint3.setShader(radial2);
@@ -445,7 +445,7 @@ protected:
         const SkPoint center = { 0, 0 };
         const SkScalar kRadius = 3000;
         const SkColor gColors[] = { 0xFFFFFFFF, 0xFF000000 };
-        fShader.reset(SkGradientShader::CreateRadial(center, kRadius, gColors, NULL, 2,
+        fShader.reset(SkGradientShader::CreateRadial(center, kRadius, gColors, nullptr, 2,
                                                      SkShader::kClamp_TileMode));
     }
 
diff --git a/gm/gradients_no_texture.cpp b/gm/gradients_no_texture.cpp
index d06ae5bdbf..3e73d1b4b3 100644
--- a/gm/gradients_no_texture.cpp
+++ b/gm/gradients_no_texture.cpp
@@ -20,10 +20,10 @@ static const SkColor gColors[] = {
 };
 
 static const GradData gGradData[] = {
-    { 1, gColors, NULL },
-    { 2, gColors, NULL },
-    { 3, gColors, NULL },
-    { 4, gColors, NULL },
+    { 1, gColors, nullptr },
+    { 2, gColors, nullptr },
+    { 3, gColors, nullptr },
+    { 4, gColors, nullptr },
 };
 
 static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
@@ -126,7 +126,7 @@ struct ColorPos {
     SkScalar*   fPos;
     int         fCount;
 
-    ColorPos() : fColors(NULL), fPos(NULL), fCount(0) {}
+    ColorPos() : fColors(nullptr), fPos(nullptr), fCount(0) {}
     ~ColorPos() {
         delete[] fColors;
         delete[] fPos;
@@ -180,7 +180,7 @@ static void make1(ColorPos* rec) {
         SK_ColorBLACK, SK_ColorWHITE, SK_ColorBLACK, SK_ColorWHITE,
         SK_ColorBLACK,
     };
-    rec->construct(colors, NULL, SK_ARRAY_COUNT(colors));
+    rec->construct(colors, nullptr, SK_ARRAY_COUNT(colors));
 }
 
 static void make2(ColorPos* rec) {
diff --git a/gm/gradtext.cpp b/gm/gradtext.cpp
index b576ede644..acb88d6e52 100644
--- a/gm/gradtext.cpp
+++ b/gm/gradtext.cpp
@@ -14,7 +14,7 @@
 static SkShader* make_grad(SkScalar width) {
     SkColor colors[] = { SK_ColorRED, 0x0000FF00, SK_ColorBLUE };
     SkPoint pts[] = { { 0, 0 }, { width, 0 } };
-    return SkGradientShader::CreateLinear(pts, colors, NULL,
+    return SkGradientShader::CreateLinear(pts, colors, nullptr,
                                           SK_ARRAY_COUNT(colors),
                                           SkShader::kMirror_TileMode);
 }
@@ -23,7 +23,7 @@ static SkShader* make_grad(SkScalar width) {
 static SkShader* make_grad2(SkScalar width) {
     SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
     SkPoint pts[] = { { 0, 0 }, { width, 0 } };
-    return SkGradientShader::CreateLinear(pts, colors, NULL,
+    return SkGradientShader::CreateLinear(pts, colors, nullptr,
                                           SK_ARRAY_COUNT(colors),
                                           SkShader::kMirror_TileMode);
 }
@@ -31,7 +31,7 @@ static SkShader* make_grad2(SkScalar width) {
 static SkShader* make_chrome_solid() {
     SkColor colors[] = { SK_ColorGREEN, SK_ColorGREEN };
     SkPoint pts[] = { { 0, 0 }, { 1, 0 } };
-    return SkGradientShader::CreateLinear(pts, colors, NULL, 2,
+    return SkGradientShader::CreateLinear(pts, colors, nullptr, 2,
                                           SkShader::kClamp_TileMode);
 }
 
diff --git a/gm/hairmodes.cpp b/gm/hairmodes.cpp
index 74eda7b913..4f85c19883 100644
--- a/gm/hairmodes.cpp
+++ b/gm/hairmodes.cpp
@@ -106,7 +106,7 @@ namespace skiagm {
                     SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
 
                     canvas->drawRect(bounds, fBGPaint);
-                    canvas->saveLayer(&bounds, NULL);
+                    canvas->saveLayer(&bounds, nullptr);
                     SkScalar dy = drawCell(canvas, mode,
                                            gAlphaValue[alpha & 1],
                                            gAlphaValue[alpha & 2]);
diff --git a/gm/image.cpp b/gm/image.cpp
index 205b4ab278..726ab97a8f 100644
--- a/gm/image.cpp
+++ b/gm/image.cpp
@@ -21,7 +21,7 @@ static void drawJpeg(SkCanvas* canvas, const SkISize& size) {
     // be exercised on machines other than mike's. Will require a
     // rebaseline.
     SkAutoDataUnref data(SkData::NewFromFileName("/Users/mike/Downloads/skia.google.jpeg"));
-    if (NULL == data.get()) {
+    if (nullptr == data.get()) {
         return;
     }
     SkImage* image = SkImage::NewFromEncoded(data);
@@ -29,7 +29,7 @@ static void drawJpeg(SkCanvas* canvas, const SkISize& size) {
         SkAutoCanvasRestore acr(canvas, true);
         canvas->scale(size.width() * 1.0f / image->width(),
                       size.height() * 1.0f / image->height());
-        canvas->drawImage(image, 0, 0, NULL);
+        canvas->drawImage(image, 0, 0, nullptr);
         image->unref();
     }
 }
@@ -76,9 +76,9 @@ static void test_surface(SkCanvas* canvas, SkSurface* surf, bool usePaint) {
 //    paint.setFilterBitmap(true);
 //    paint.setAlpha(0x80);
 
-    canvas->drawImage(imgR, 0, 0, usePaint ? &paint : NULL);
-    canvas->drawImage(imgG, 0, 80, usePaint ? &paint : NULL);
-    surf->draw(canvas, 0, 160, usePaint ? &paint : NULL);
+    canvas->drawImage(imgR, 0, 0, usePaint ? &paint : nullptr);
+    canvas->drawImage(imgG, 0, 80, usePaint ? &paint : nullptr);
+    surf->draw(canvas, 0, 160, usePaint ? &paint : nullptr);
 
     SkRect src1, src2, src3;
     src1.iset(0, 0, surf->width(), surf->height());
@@ -92,10 +92,10 @@ static void test_surface(SkCanvas* canvas, SkSurface* surf, bool usePaint) {
     dst3.set(0, 400, 65, 465);
     dst4.set(0, 480, 65, 545);
 
-    canvas->drawImageRect(imgR, src1, dst1, usePaint ? &paint : NULL);
-    canvas->drawImageRect(imgG, src2, dst2, usePaint ? &paint : NULL);
-    canvas->drawImageRect(imgR, src3, dst3, usePaint ? &paint : NULL);
-    canvas->drawImageRect(imgG, dst4, usePaint ? &paint : NULL);
+    canvas->drawImageRect(imgR, src1, dst1, usePaint ? &paint : nullptr);
+    canvas->drawImageRect(imgG, src2, dst2, usePaint ? &paint : nullptr);
+    canvas->drawImageRect(imgR, src3, dst3, usePaint ? &paint : nullptr);
+    canvas->drawImageRect(imgG, dst4, usePaint ? &paint : nullptr);
 
     imgG->unref();
     imgR->unref();
@@ -241,20 +241,20 @@ protected:
         if (subset) {
             srcR.set(*subset);
         }
-        canvas->legacy_drawImageRect(image, subset ? &srcR : NULL, dstR, &paint);
+        canvas->legacy_drawImageRect(image, subset ? &srcR : nullptr, dstR, &paint);
         canvas->translate(newW + 20.0f, 0);
 
         // image method
         SkAutoTUnref<SkImage> image2(image->newImage(newW, newH, subset, fq));
-        canvas->drawImage(image2, 0, 0, NULL);
+        canvas->drawImage(image2, 0, 0, nullptr);
         canvas->translate(image2->width() + 20.0f, 0);
     }
 
     void drawImage(SkCanvas* canvas, SkImage* image, SkFilterQuality fq) {
 
-        canvas->drawImage(image, 0, 0, NULL);
+        canvas->drawImage(image, 0, 0, nullptr);
         canvas->translate(image->width() + 20.0f, 0);
-        this->drawResized(canvas, image, image->width()*4/10, image->height()*4/10, NULL, fq);
+        this->drawResized(canvas, image, image->width()*4/10, image->height()*4/10, nullptr, fq);
 
         SkIRect subset = SkIRect::MakeLTRB(W/4, H/4, W/2, H/2);
         this->drawResized(canvas, image, W, H, &subset, fq);
diff --git a/gm/imagealphathreshold.cpp b/gm/imagealphathreshold.cpp
index a418f0fe68..13a0ffa90b 100644
--- a/gm/imagealphathreshold.cpp
+++ b/gm/imagealphathreshold.cpp
@@ -47,7 +47,7 @@ protected:
         SkPaint paint;
         paint.setImageFilter(
             SkAlphaThresholdFilter::Create(region, 0.2f, 0.7f))->unref();
-        canvas->saveLayer(NULL, &paint);
+        canvas->saveLayer(nullptr, &paint);
         paint.setAntiAlias(true);
 
         SkPaint rect_paint;
diff --git a/gm/imageblur.cpp b/gm/imageblur.cpp
index efb5988d65..f6ac0982b7 100644
--- a/gm/imageblur.cpp
+++ b/gm/imageblur.cpp
@@ -35,7 +35,7 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         SkPaint paint;
         paint.setImageFilter(SkBlurImageFilter::Create(fSigmaX, fSigmaY))->unref();
-        canvas->saveLayer(NULL, &paint);
+        canvas->saveLayer(nullptr, &paint);
         const char* str = "The quick brown fox jumped over the lazy dog.";
 
         SkRandom rand;
diff --git a/gm/imageblur2.cpp b/gm/imageblur2.cpp
index 58e40961e4..223582f120 100644
--- a/gm/imageblur2.cpp
+++ b/gm/imageblur2.cpp
@@ -59,7 +59,7 @@ protected:
 
                 SkPaint paint;
                 paint.setImageFilter(SkBlurImageFilter::Create(sigmaX, sigmaY))->unref();
-                canvas->saveLayer(NULL, &paint);
+                canvas->saveLayer(nullptr, &paint);
 
                 SkRandom rand;
                 SkPaint textPaint;
diff --git a/gm/imageblurtiled.cpp b/gm/imageblurtiled.cpp
index ed4ae6cef3..68e5785ddf 100644
--- a/gm/imageblurtiled.cpp
+++ b/gm/imageblurtiled.cpp
@@ -41,7 +41,7 @@ protected:
             for (SkScalar x = bounds.left(); x < bounds.right(); x += tile_size) {
                 canvas->save();
                 canvas->clipRect(SkRect::MakeXYWH(x, y, tile_size, tile_size));
-                canvas->saveLayer(NULL, &paint);
+                canvas->saveLayer(nullptr, &paint);
                 const char* str[] = {
                     "The quick",
                     "brown fox",
diff --git a/gm/imagefilters.cpp b/gm/imagefilters.cpp
index 54e50e47f2..e28bf5255e 100644
--- a/gm/imagefilters.cpp
+++ b/gm/imagefilters.cpp
@@ -31,7 +31,7 @@ protected:
         // want to force a layer, so modes like DstIn can combine meaningfully, but the final
         // image can still be shown against our default (opaque) background. non-opaque GMs
         // are a lot more trouble to compare/triage.
-        canvas->saveLayer(NULL, NULL);
+        canvas->saveLayer(nullptr, nullptr);
         canvas->drawColor(SK_ColorGREEN);
 
         SkPaint paint;
@@ -62,7 +62,7 @@ protected:
         
         for (size_t i = 0; i < SK_ARRAY_COUNT(modes); ++i) {
             canvas->save();
-            this->doDraw(canvas, modes[i], NULL);
+            this->doDraw(canvas, modes[i], nullptr);
             canvas->translate(240, 0);
             this->doDraw(canvas, modes[i], imf);
             canvas->restore();
diff --git a/gm/imagefiltersbase.cpp b/gm/imagefiltersbase.cpp
index 61c3f11f58..0101a9c2a0 100644
--- a/gm/imagefiltersbase.cpp
+++ b/gm/imagefiltersbase.cpp
@@ -32,7 +32,7 @@ public:
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(FailImageFilter)
 
 protected:
-    FailImageFilter() : INHERITED(0, NULL) {}
+    FailImageFilter() : INHERITED(0, nullptr) {}
 
     bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
                        SkBitmap* result, SkIPoint* offset) const override {
@@ -67,7 +67,7 @@ public:
                                     IdentityImageFilter::GetFlattenableType());
         }
     };
-    static IdentityImageFilter* Create(SkImageFilter* input = NULL) {
+    static IdentityImageFilter* Create(SkImageFilter* input = nullptr) {
         return new IdentityImageFilter(input);
     }
 
@@ -160,7 +160,7 @@ static void draw_bitmap(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     bm.allocN32Pixels(bounds.width(), bounds.height());
     bm.eraseColor(SK_ColorTRANSPARENT);
     SkCanvas c(bm);
-    draw_path(&c, r, NULL);
+    draw_path(&c, r, nullptr);
 
     canvas->drawBitmap(bm, 0, 0, &paint);
 }
@@ -176,7 +176,7 @@ static void draw_sprite(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     bm.allocN32Pixels(bounds.width(), bounds.height());
     bm.eraseColor(SK_ColorTRANSPARENT);
     SkCanvas c(bm);
-    draw_path(&c, r, NULL);
+    draw_path(&c, r, nullptr);
 
     SkPoint loc = { r.fLeft, r.fTop };
     canvas->getTotalMatrix().mapPoints(&loc, 1);
@@ -216,7 +216,7 @@ protected:
         SkColorFilter* cf = SkColorFilter::CreateModeFilter(SK_ColorRED,
                                                      SkXfermode::kSrcIn_Mode);
         SkImageFilter* filters[] = {
-            NULL,
+            nullptr,
             IdentityImageFilter::Create(),
             FailImageFilter::Create(),
             SkColorFilterImageFilter::Create(cf),
@@ -309,8 +309,8 @@ protected:
                     this->installFilter(&paint);
                 }
                 if (doSaveLayer) {
-                    canvas->saveLayer(NULL, &paint);
-                    paint.setImageFilter(NULL);
+                    canvas->saveLayer(nullptr, &paint);
+                    paint.setImageFilter(nullptr);
                 }
                 this->drawWaterfall(canvas, paint);
 
diff --git a/gm/imagefiltersclipped.cpp b/gm/imagefiltersclipped.cpp
index a641ca3473..362d327b37 100644
--- a/gm/imagefiltersclipped.cpp
+++ b/gm/imagefiltersclipped.cpp
@@ -53,7 +53,7 @@ protected:
         colors[0] = SK_ColorWHITE;
         colors[1] = SK_ColorBLACK;
         SkAutoTUnref<SkShader> shader(
-            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, NULL, 2,
+            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, nullptr, 2,
                                            SkShader::kClamp_TileMode)
         );
         SkPaint paint;
diff --git a/gm/imagefilterscropexpand.cpp b/gm/imagefilterscropexpand.cpp
index 8f90fb14bd..cfbf13a759 100644
--- a/gm/imagefilterscropexpand.cpp
+++ b/gm/imagefilterscropexpand.cpp
@@ -68,7 +68,7 @@ protected:
         colors[0] = SK_ColorWHITE;
         colors[1] = SK_ColorBLACK;
         SkAutoTUnref<SkShader> shader(
-            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, NULL, 2,
+            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, nullptr, 2,
                                            SkShader::kClamp_TileMode)
         );
         SkPaint paint;
@@ -105,7 +105,7 @@ protected:
         SkAutoTUnref<SkImageFilter> gradient_circle_source(
             SkBitmapSource::Create(gradient_circle));
         SkAutoTUnref<SkImageFilter> noop_cropped(
-            SkOffsetImageFilter::Create(0, 0, NULL, &crop_rect));
+            SkOffsetImageFilter::Create(0, 0, nullptr, &crop_rect));
         SkScalar sk255 = SkIntToScalar(255);
         SkScalar matrix[20] = { 1, 0, 0, 0, 0,
                                 0, 1, 0, 0, sk255,
diff --git a/gm/imagefilterscropped.cpp b/gm/imagefilterscropped.cpp
index c5bef7b3f8..92e45ea499 100644
--- a/gm/imagefilterscropped.cpp
+++ b/gm/imagefilterscropped.cpp
@@ -60,7 +60,7 @@ static void draw_bitmap(SkCanvas* canvas, const SkRect& r, SkImageFilter* imf) {
     bm.allocN32Pixels(bounds.width(), bounds.height());
     bm.eraseColor(SK_ColorTRANSPARENT);
     SkCanvas c(bm);
-    draw_path(&c, r, NULL);
+    draw_path(&c, r, nullptr);
 
     paint.setImageFilter(imf);
     canvas->drawBitmap(bm, 0, 0, &paint);
@@ -149,23 +149,23 @@ protected:
 
         SkAutoTUnref<SkImageFilter> cfOffset(SkColorFilterImageFilter::Create(cf.get(), offset.get()));
 
-        SkAutoTUnref<SkImageFilter> erodeX(SkErodeImageFilter::Create(8, 0, NULL, &cropRect));
-        SkAutoTUnref<SkImageFilter> erodeY(SkErodeImageFilter::Create(0, 8, NULL, &cropRect));
+        SkAutoTUnref<SkImageFilter> erodeX(SkErodeImageFilter::Create(8, 0, nullptr, &cropRect));
+        SkAutoTUnref<SkImageFilter> erodeY(SkErodeImageFilter::Create(0, 8, nullptr, &cropRect));
 
         SkImageFilter* filters[] = {
-            NULL,
-            SkColorFilterImageFilter::Create(cf.get(), NULL, &cropRect),
-            SkBlurImageFilter::Create(1.0f, 1.0f, NULL, &cropRect),
-            SkBlurImageFilter::Create(8.0f, 0.0f, NULL, &cropRect),
-            SkBlurImageFilter::Create(0.0f, 8.0f, NULL, &cropRect),
-            SkBlurImageFilter::Create(8.0f, 8.0f, NULL, &cropRect),
-            SkErodeImageFilter::Create(1, 1, NULL, &cropRect),
+            nullptr,
+            SkColorFilterImageFilter::Create(cf.get(), nullptr, &cropRect),
+            SkBlurImageFilter::Create(1.0f, 1.0f, nullptr, &cropRect),
+            SkBlurImageFilter::Create(8.0f, 0.0f, nullptr, &cropRect),
+            SkBlurImageFilter::Create(0.0f, 8.0f, nullptr, &cropRect),
+            SkBlurImageFilter::Create(8.0f, 8.0f, nullptr, &cropRect),
+            SkErodeImageFilter::Create(1, 1, nullptr, &cropRect),
             SkErodeImageFilter::Create(8, 0, erodeY, &cropRect),
             SkErodeImageFilter::Create(0, 8, erodeX, &cropRect),
-            SkErodeImageFilter::Create(8, 8, NULL, &cropRect),
-            SkMergeImageFilter::Create(NULL, cfOffset.get(), SkXfermode::kSrcOver_Mode, &cropRect),
-            SkBlurImageFilter::Create(8.0f, 8.0f, NULL, &bogusRect),
-            SkColorFilterImageFilter::Create(cf.get(), NULL, &bogusRect),
+            SkErodeImageFilter::Create(8, 8, nullptr, &cropRect),
+            SkMergeImageFilter::Create(nullptr, cfOffset.get(), SkXfermode::kSrcOver_Mode, &cropRect),
+            SkBlurImageFilter::Create(8.0f, 8.0f, nullptr, &bogusRect),
+            SkColorFilterImageFilter::Create(cf.get(), nullptr, &bogusRect),
         };
 
         SkRect r = SkRect::MakeWH(SkIntToScalar(64), SkIntToScalar(64));
diff --git a/gm/imagefiltersgraph.cpp b/gm/imagefiltersgraph.cpp
index 521dd3c7ef..66b32e99c3 100644
--- a/gm/imagefiltersgraph.cpp
+++ b/gm/imagefiltersgraph.cpp
@@ -194,7 +194,7 @@ protected:
             SkAutoTUnref<SkXfermode> mode(SkXfermode::Create(SkXfermode::kSrcIn_Mode));
             SkImageFilter::CropRect cropRect(SkRect::MakeWH(SkIntToScalar(95), SkIntToScalar(100)));
             SkAutoTUnref<SkImageFilter> blend(
-                SkXfermodeImageFilter::Create(mode, blur, NULL, &cropRect));
+                SkXfermodeImageFilter::Create(mode, blur, nullptr, &cropRect));
 
             SkPaint paint;
             paint.setImageFilter(blend);
@@ -211,7 +211,7 @@ protected:
                                                                SkIntToScalar(80), SkIntToScalar(80)));
             SkImageFilter::CropRect innerRect(SkRect::MakeXYWH(SkIntToScalar(20), SkIntToScalar(20),
                                                                SkIntToScalar(60), SkIntToScalar(60)));
-            SkAutoTUnref<SkImageFilter> color1(SkColorFilterImageFilter::Create(cf1, NULL, &outerRect));
+            SkAutoTUnref<SkImageFilter> color1(SkColorFilterImageFilter::Create(cf1, nullptr, &outerRect));
             SkAutoTUnref<SkImageFilter> color2(SkColorFilterImageFilter::Create(cf2, color1, &innerRect));
 
             SkPaint paint;
diff --git a/gm/imagefiltersscaled.cpp b/gm/imagefiltersscaled.cpp
index 2e4756a9b3..b53263606c 100644
--- a/gm/imagefiltersscaled.cpp
+++ b/gm/imagefiltersscaled.cpp
@@ -52,7 +52,7 @@ protected:
         colors[0] = SK_ColorWHITE;
         colors[1] = SK_ColorBLACK;
         SkAutoTUnref<SkShader> shader(
-            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, NULL, 2,
+            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, nullptr, 2,
                                            SkShader::kClamp_TileMode)
         );
         SkPaint paint;
diff --git a/gm/imagefilterstransformed.cpp b/gm/imagefilterstransformed.cpp
index 794a47167a..9259ce4fce 100644
--- a/gm/imagefilterstransformed.cpp
+++ b/gm/imagefilterstransformed.cpp
@@ -45,7 +45,7 @@ protected:
         colors[0] = SK_ColorWHITE;
         colors[1] = SK_ColorBLACK;
         SkAutoTUnref<SkShader> shader(
-            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, NULL, 2,
+            SkGradientShader::CreateRadial(SkPoint::Make(x, y), radius, colors, nullptr, 2,
                                            SkShader::kClamp_TileMode)
         );
         SkPaint paint;
diff --git a/gm/imagefromyuvtextures.cpp b/gm/imagefromyuvtextures.cpp
index 68faf801c6..faa3eefa7e 100644
--- a/gm/imagefromyuvtextures.cpp
+++ b/gm/imagefromyuvtextures.cpp
@@ -41,7 +41,7 @@ protected:
         static const SkColor kColors[] =
             { SK_ColorBLUE, SK_ColorYELLOW, SK_ColorGREEN, SK_ColorWHITE };
         paint.setShader(SkGradientShader::CreateRadial(SkPoint::Make(0,0), kBmpSize / 2.f, kColors,
-                                                       NULL, SK_ARRAY_COUNT(kColors),
+                                                       nullptr, SK_ARRAY_COUNT(kColors),
                                                        SkShader::kMirror_TileMode))->unref();
         SkBitmap rgbBmp;
         rgbBmp.allocN32Pixels(kBmpSize, kBmpSize, true);
@@ -156,7 +156,7 @@ protected:
 
             canvas->drawImage(images[i], x, y);
             images[i]->unref();
-            images[i] = NULL;
+            images[i] = nullptr;
         }
      }
 
diff --git a/gm/imagemagnifier.cpp b/gm/imagemagnifier.cpp
index ac1941c121..2bf22262dc 100644
--- a/gm/imagemagnifier.cpp
+++ b/gm/imagemagnifier.cpp
@@ -38,7 +38,7 @@ protected:
                                  SkIntToScalar(WIDTH / 2),
                                  SkIntToScalar(HEIGHT / 2)),
                 100))->unref();
-        canvas->saveLayer(NULL, &filterPaint);
+        canvas->saveLayer(nullptr, &filterPaint);
         const char* str = "The quick brown fox jumped over the lazy dog.";
         SkRandom rand;
         for (int i = 0; i < 25; ++i) {
diff --git a/gm/imageresizetiled.cpp b/gm/imageresizetiled.cpp
index bc640bc6aa..1da2bcea3a 100644
--- a/gm/imageresizetiled.cpp
+++ b/gm/imageresizetiled.cpp
@@ -47,7 +47,7 @@ protected:
                 canvas->clipRect(SkRect::MakeXYWH(x, y, tile_size, tile_size));
                 canvas->scale(SkScalarInvert(RESIZE_FACTOR),
                               SkScalarInvert(RESIZE_FACTOR));
-                canvas->saveLayer(NULL, &paint);
+                canvas->saveLayer(nullptr, &paint);
                 const char* str[] = {
                     "The quick",
                     "brown fox",
diff --git a/gm/lerpmode.cpp b/gm/lerpmode.cpp
index f690c76fa6..bcf17c37a8 100644
--- a/gm/lerpmode.cpp
+++ b/gm/lerpmode.cpp
@@ -18,7 +18,7 @@ static void show_circlelayers(SkCanvas* canvas, SkXfermode* mode) {
     r.fRight = bounds.centerX();
     canvas->drawRect(r, paint);
 
-    canvas->saveLayer(&bounds, NULL);
+    canvas->saveLayer(&bounds, nullptr);
 
     paint.setColor(0x80FF0000);
     r = bounds;
@@ -48,7 +48,7 @@ protected:
     }
 
     void onDraw(SkCanvas* canvas) override {
-        show_circlelayers(canvas, NULL);
+        show_circlelayers(canvas, nullptr);
         canvas->translate(150, 0);
         SkAutoTUnref<SkXfermode> mode(SkLerpXfermode::Create(0.5f));
         show_circlelayers(canvas, mode.get());
diff --git a/gm/lighting.cpp b/gm/lighting.cpp
index a464a07480..d68e67db16 100644
--- a/gm/lighting.cpp
+++ b/gm/lighting.cpp
@@ -93,12 +93,12 @@ protected:
 
         SkImageFilter::CropRect cropRect(SkRect::MakeXYWH(20, 10, 60, 65));
         SkImageFilter::CropRect fullSizeCropRect(SkRect::MakeXYWH(0, 0, 100, 100));
-        SkAutoTUnref<SkImageFilter> noopCropped(SkOffsetImageFilter::Create(0, 0, NULL, &cropRect));
+        SkAutoTUnref<SkImageFilter> noopCropped(SkOffsetImageFilter::Create(0, 0, nullptr, &cropRect));
 
         int y = 0;
         for (int i = 0; i < 3; i++) {
-            const SkImageFilter::CropRect* cr = (i == 1) ? &cropRect : (i == 2) ? &fullSizeCropRect : NULL;
-            SkImageFilter* input = (i == 2) ? noopCropped.get() : NULL;
+            const SkImageFilter::CropRect* cr = (i == 1) ? &cropRect : (i == 2) ? &fullSizeCropRect : nullptr;
+            SkImageFilter* input = (i == 2) ? noopCropped.get() : nullptr;
             paint.setImageFilter(SkLightingImageFilter::CreatePointLitDiffuse(pointLocation,
                                                                               white,
                                                                               surfaceScale,
diff --git a/gm/lumafilter.cpp b/gm/lumafilter.cpp
index 46a22f84c4..3244b2b055 100644
--- a/gm/lumafilter.cpp
+++ b/gm/lumafilter.cpp
@@ -38,7 +38,7 @@ static void draw_scene(SkCanvas* canvas, SkColorFilter* filter,
     paint.setARGB(0x20, 0, 0, 0xff);
     canvas->drawRect(bounds, paint);
 
-    canvas->saveLayer(&bounds, NULL);
+    canvas->saveLayer(&bounds, nullptr);
 
     r = bounds;
     r.inset(kInset, 0);
@@ -119,9 +119,9 @@ protected:
             SkShader*   fShader1;
             SkShader*   fShader2;
         } shaders[] = {
-            { NULL, NULL },
-            { NULL, fGr2 },
-            { fGr1, NULL },
+            { nullptr, nullptr },
+            { nullptr, fGr2 },
+            { fGr1, nullptr },
             { fGr1, fGr2 },
         };
 
diff --git a/gm/matrixconvolution.cpp b/gm/matrixconvolution.cpp
index b912f90cfe..1e6a49d4b6 100644
--- a/gm/matrixconvolution.cpp
+++ b/gm/matrixconvolution.cpp
@@ -49,7 +49,7 @@ protected:
 
     void draw(SkCanvas* canvas, int x, int y, const SkIPoint& kernelOffset,
               SkMatrixConvolutionImageFilter::TileMode tileMode, bool convolveAlpha,
-              const SkImageFilter::CropRect* cropRect = NULL) {
+              const SkImageFilter::CropRect* cropRect = nullptr) {
         SkScalar kernel[9] = {
             SkIntToScalar( 1), SkIntToScalar( 1), SkIntToScalar( 1),
             SkIntToScalar( 1), SkIntToScalar(-7), SkIntToScalar( 1),
@@ -66,7 +66,7 @@ protected:
                                                    kernelOffset,
                                                    tileMode,
                                                    convolveAlpha,
-                                                   NULL,
+                                                   nullptr,
                                                    cropRect));
         paint.setImageFilter(filter);
         canvas->save();
diff --git a/gm/mipmap.cpp b/gm/mipmap.cpp
index 596cc19d6e..4eb5c2aa3c 100644
--- a/gm/mipmap.cpp
+++ b/gm/mipmap.cpp
@@ -45,7 +45,7 @@ static void test_mip(SkCanvas* canvas) {
         canvas->drawImageRect(img, dst, &paint);
         canvas->translate(0, 20);
     }
-    canvas->drawImage(img, 20, 20, NULL);
+    canvas->drawImage(img, 20, 20, nullptr);
 }
 
 class MipMapGM : public skiagm::GM {
diff --git a/gm/modecolorfilters.cpp b/gm/modecolorfilters.cpp
index 9f70bf8674..b5ede710f1 100644
--- a/gm/modecolorfilters.cpp
+++ b/gm/modecolorfilters.cpp
@@ -20,7 +20,7 @@ static SkShader* make_color_shader(SkColor color) {
     static const SkPoint kPts[] = {{0, 0}, {1, 1}};
     SkColor colors[] = {color, color};
 
-    return SkGradientShader::CreateLinear(kPts, colors, NULL, 2, SkShader::kClamp_TileMode);
+    return SkGradientShader::CreateLinear(kPts, colors, nullptr, 2, SkShader::kClamp_TileMode);
 }
 
 static SkShader* make_solid_shader() {
@@ -82,7 +82,7 @@ protected:
         bgPaint.setXfermodeMode(SkXfermode::kSrc_Mode);
 
         SkShader* shaders[] = {
-            NULL,                                   // use a paint color instead of a shader
+            nullptr,                                   // use a paint color instead of a shader
             make_solid_shader(),
             make_transparent_shader(),
             make_trans_black_shader(),
@@ -127,7 +127,7 @@ protected:
                 paint.setColorFilter(cf);
                 for (size_t s = 0; s < SK_ARRAY_COUNT(shaders); ++s) {
                     paint.setShader(shaders[s]);
-                    bool hasShader = NULL == paint.getShader();
+                    bool hasShader = nullptr == paint.getShader();
                     int paintColorCnt = hasShader ? SK_ARRAY_COUNT(alphas) : SK_ARRAY_COUNT(colors);
                     SkColor* paintColors = hasShader ? alphas : colors;
                     for (int pc = 0; pc < paintColorCnt; ++pc) {
@@ -137,7 +137,7 @@ protected:
                         SkRect rect = SkRect::MakeXYWH(x * kRectWidth, y * kRectHeight,
                                                        SkIntToScalar(kRectWidth),
                                                        SkIntToScalar(kRectHeight));
-                        canvas->saveLayer(&rect, NULL);
+                        canvas->saveLayer(&rect, nullptr);
                         canvas->drawRect(rect, bgPaint);
                         canvas->drawRect(rect, paint);
                         canvas->restore();
diff --git a/gm/morphology.cpp b/gm/morphology.cpp
index cb321c6efd..3fb11d82d1 100644
--- a/gm/morphology.cpp
+++ b/gm/morphology.cpp
@@ -73,18 +73,18 @@ protected:
 
         for (unsigned j = 0; j < 4; ++j) {
             for (unsigned i = 0; i < SK_ARRAY_COUNT(samples); ++i) {
-                const SkImageFilter::CropRect* cr = j & 0x02 ? &cropRect : NULL;
+                const SkImageFilter::CropRect* cr = j & 0x02 ? &cropRect : nullptr;
                 if (j & 0x01) {
                     paint.setImageFilter(SkErodeImageFilter::Create(
                         samples[i].fRadiusX,
                         samples[i].fRadiusY,
-                        NULL,
+                        nullptr,
                         cr))->unref();
                 } else {
                     paint.setImageFilter(SkDilateImageFilter::Create(
                         samples[i].fRadiusX,
                         samples[i].fRadiusY,
-                        NULL,
+                        nullptr,
                         cr))->unref();
                 }
                 drawClippedBitmap(canvas, paint, i * 140, j * 140);
diff --git a/gm/multipicturedraw.cpp b/gm/multipicturedraw.cpp
index 3a0b0fa7d9..88d6cd798f 100644
--- a/gm/multipicturedraw.cpp
+++ b/gm/multipicturedraw.cpp
@@ -68,7 +68,7 @@ static const SkPicture* make_hex_plane_picture(SkColor fillColor) {
         xPos = 0;
 
         for (int x = 0; x < kNumHexX; ++x) {
-            canvas->saveLayer(NULL, NULL);
+            canvas->saveLayer(nullptr, nullptr);
             canvas->translate(xPos, yPos + ((x % 2) ? kRoot3Over2 * kHexSide : 0));
             canvas->drawPath(hex, fill);
             canvas->drawPath(hex, stroke);
@@ -111,7 +111,7 @@ static const SkPicture* make_single_layer_hex_plane_picture() {
     SkCanvas* canvas = recorder.beginRecording(kBig, kBig, &bbhFactory,
                                                SkPictureRecorder::kComputeSaveLayerInfo_RecordFlag);
 
-    canvas->saveLayer(NULL, NULL);
+    canvas->saveLayer(nullptr, nullptr);
 
     SkScalar xPos = 0.0f, yPos = 0.0f;
 
@@ -171,7 +171,7 @@ static const SkPicture* make_tri_picture() {
     r.outset(2.0f, 2.0f);       // outset for stroke
     canvas->clipRect(r);
     // The saveLayer/restore block is to exercise layer hoisting
-    canvas->saveLayer(NULL, NULL);
+    canvas->saveLayer(nullptr, nullptr);
         canvas->drawPath(tri, fill);
         canvas->drawPath(tri, stroke);
     canvas->restore();
@@ -245,8 +245,8 @@ static SkSurface* create_compat_surface(SkCanvas* canvas, int width, int height)
     SkImageInfo info = SkImageInfo::MakeN32Premul(width, height);
 
     SkSurface* surface = canvas->newSurface(info);
-    if (NULL == surface) {
-        // picture canvas returns NULL so fall back to raster
+    if (nullptr == surface) {
+        // picture canvas returns nullptr so fall back to raster
         surface = SkSurface::NewRaster(info);
     }
 
@@ -257,7 +257,7 @@ static SkSurface* create_compat_surface(SkCanvas* canvas, int width, int height)
 // fragments potentially generated by the MultiPictureDraw object
 class ComposeStep {
 public:
-    ComposeStep() : fSurf(NULL), fX(0.0f), fY(0.0f), fPaint(NULL) { }
+    ComposeStep() : fSurf(nullptr), fX(0.0f), fY(0.0f), fPaint(nullptr) { }
     ~ComposeStep() {
         SkSafeUnref(fSurf);
         delete fPaint;
@@ -474,7 +474,7 @@ namespace skiagm {
             SkASSERT(SK_ARRAY_COUNT(gContentMthds) == kContentCnt);
 
             for (int i = 0; i < kNumPictures; ++i) {
-                fPictures[i] = NULL;
+                fPictures[i] = nullptr;
             }
         }
 
diff --git a/gm/ninepatchstretch.cpp b/gm/ninepatchstretch.cpp
index 267c41587b..4074add1bb 100644
--- a/gm/ninepatchstretch.cpp
+++ b/gm/ninepatchstretch.cpp
@@ -70,7 +70,7 @@ protected:
     }
 
     void onDraw(SkCanvas* canvas) override {
-        if (NULL == fBitmap.pixelRef()) {
+        if (nullptr == fBitmap.pixelRef()) {
             fImage.reset(make_image(canvas, &fCenter));
             image_to_bitmap(fImage, &fBitmap);
         }
@@ -85,7 +85,7 @@ protected:
             { fixed * 4,     fixed * 4 }
         };
 
-        canvas->drawBitmap(fBitmap, 10, 10, NULL);
+        canvas->drawBitmap(fBitmap, 10, 10, nullptr);
 
         SkScalar x = SkIntToScalar(100);
         SkScalar y = SkIntToScalar(100);
diff --git a/gm/offsetimagefilter.cpp b/gm/offsetimagefilter.cpp
index 35ccc053c4..fdf2aa85fa 100644
--- a/gm/offsetimagefilter.cpp
+++ b/gm/offsetimagefilter.cpp
@@ -96,7 +96,7 @@ protected:
 
         SkIRect cropRect = SkIRect::MakeXYWH(0, 0, 100, 100);
         SkImageFilter::CropRect rect(SkRect::Make(cropRect));
-        SkAutoTUnref<SkImageFilter> filter(SkOffsetImageFilter::Create(-5, -10, NULL, &rect));
+        SkAutoTUnref<SkImageFilter> filter(SkOffsetImageFilter::Create(-5, -10, nullptr, &rect));
         paint.setImageFilter(filter);
         drawClippedBitmap(canvas, fBitmap, paint, 2, cropRect);
     }
@@ -120,7 +120,7 @@ protected:
     SkISize onISize() override { return SkISize::Make(640, 200); }
     
     void doDraw(SkCanvas* canvas, const SkRect& r, SkImageFilter* imgf,
-                const SkRect* clipR = NULL) {
+                const SkRect* clipR = nullptr) {
         SkPaint p;
 
         if (clipR) {
@@ -167,23 +167,23 @@ protected:
         canvas->translate(40, 40);
         
         canvas->save();
-        this->doDraw(canvas, r, NULL);
+        this->doDraw(canvas, r, nullptr);
         
         canvas->translate(100, 0);
         this->doDraw(canvas, r, SkOffsetImageFilter::Create(20, 20));
         
         canvas->translate(100, 0);
-        this->doDraw(canvas, r, SkOffsetImageFilter::Create(20, 20, NULL, &cr0));
+        this->doDraw(canvas, r, SkOffsetImageFilter::Create(20, 20, nullptr, &cr0));
         
         canvas->translate(100, 0);
         this->doDraw(canvas, r, SkOffsetImageFilter::Create(20, 20), &r);
         
         canvas->translate(100, 0);
-        this->doDraw(canvas, r, SkOffsetImageFilter::Create(20, 20, NULL, &cr1));
+        this->doDraw(canvas, r, SkOffsetImageFilter::Create(20, 20, nullptr, &cr1));
         
         SkRect clipR = SkRect::MakeXYWH(40, 40, 40, 40);
         canvas->translate(100, 0);
-        this->doDraw(canvas, r, SkOffsetImageFilter::Create(20, 20, NULL, NULL), &clipR);
+        this->doDraw(canvas, r, SkOffsetImageFilter::Create(20, 20, nullptr, nullptr), &clipR);
         canvas->restore();
 
         // 2nd row
@@ -194,19 +194,19 @@ protected:
          */
 
         // crop==clip==src
-        this->doDraw(canvas, r, SkOffsetImageFilter::Create(40, 0, NULL, &cr0), &r);
+        this->doDraw(canvas, r, SkOffsetImageFilter::Create(40, 0, nullptr, &cr0), &r);
 
         // crop==src, clip==dst
         canvas->translate(100, 0);
-        this->doDraw(canvas, r, SkOffsetImageFilter::Create(40, 0, NULL, &cr0), &r2);
+        this->doDraw(canvas, r, SkOffsetImageFilter::Create(40, 0, nullptr, &cr0), &r2);
 
         // crop==dst, clip==src
         canvas->translate(100, 0);
-        this->doDraw(canvas, r, SkOffsetImageFilter::Create(40, 0, NULL, &cr2), &r);
+        this->doDraw(canvas, r, SkOffsetImageFilter::Create(40, 0, nullptr, &cr2), &r);
 
         // crop==clip==dst
         canvas->translate(100, 0);
-        this->doDraw(canvas, r, SkOffsetImageFilter::Create(40, 0, NULL, &cr2), &r2);
+        this->doDraw(canvas, r, SkOffsetImageFilter::Create(40, 0, nullptr, &cr2), &r2);
     }
 
 private:
diff --git a/gm/ovals.cpp b/gm/ovals.cpp
index 32c9e71640..e4cc46eb21 100755
--- a/gm/ovals.cpp
+++ b/gm/ovals.cpp
@@ -267,7 +267,7 @@ protected:
             canvas->drawRect(oval, rectPaint);
             canvas->drawOval(oval, fPaints[i]);
 
-            fPaints[i].setShader(NULL);
+            fPaints[i].setShader(nullptr);
 
             canvas->restore();
         }
diff --git a/gm/patch.cpp b/gm/patch.cpp
index df3a84e534..c3e43004a6 100644
--- a/gm/patch.cpp
+++ b/gm/patch.cpp
@@ -17,7 +17,7 @@ static SkShader* make_shader() {
     };
     const SkPoint pts[] = { { 100.f / 4.f, 0.f }, { 3.f * 100.f / 4.f, 100.f } };
     
-    return SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
+    return SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
                                           SkShader::kMirror_TileMode);
 }
 
@@ -124,20 +124,20 @@ protected:
                 canvas->translate(x * 350.0f, y * 350.0f);
                 switch (x) {
                     case 0:
-                        canvas->drawPatch(cubics, NULL, NULL, xfer, paint);
+                        canvas->drawPatch(cubics, nullptr, nullptr, xfer, paint);
                         break;
                     case 1:
-                        canvas->drawPatch(cubics, colors, NULL, xfer, paint);
+                        canvas->drawPatch(cubics, colors, nullptr, xfer, paint);
                         break;
                     case 2:
                         paint.setShader(shader);
-                        canvas->drawPatch(cubics, NULL, texCoords, xfer, paint);
-                        paint.setShader(NULL);
+                        canvas->drawPatch(cubics, nullptr, texCoords, xfer, paint);
+                        paint.setShader(nullptr);
                         break;
                     case 3:
                         paint.setShader(shader);
                         canvas->drawPatch(cubics, colors, texCoords, xfer, paint);
-                        paint.setShader(NULL);
+                        paint.setShader(nullptr);
                         break;
                     default:
                         break;
diff --git a/gm/patchgrid.cpp b/gm/patchgrid.cpp
index 89a9847271..6f77d48a88 100644
--- a/gm/patchgrid.cpp
+++ b/gm/patchgrid.cpp
@@ -110,7 +110,7 @@ protected:
         static const int kCols = 4;
         
         canvas->scale(3, 3);
-        SkPatchGrid grid(kRows, kCols, SkPatchGrid::kColors_VertexType, NULL);
+        SkPatchGrid grid(kRows, kCols, SkPatchGrid::kColors_VertexType, nullptr);
         for (int i = 0; i < kRows; i++) {
             for (int j = 0; j < kCols; j++) {
                 SkPoint points[12];
@@ -137,7 +137,7 @@ protected:
                 colors[3] = cornerColors[i + 1][j];
                 colors[2] = cornerColors[i + 1][j + 1];
                 
-                grid.setPatch(j, i, points, colors, NULL);
+                grid.setPatch(j, i, points, colors, nullptr);
             }
         }
         
@@ -146,7 +146,7 @@ protected:
         for (int y = 0; y < dims.height(); y++) {
             for (int x = 0; x < dims.width(); x++) {
                 SkPoint cubics[12];
-                grid.getPatch(x, y, cubics, NULL, NULL);
+                grid.getPatch(x, y, cubics, nullptr, nullptr);
                 draw_control_points(canvas, cubics);
             }
         }
diff --git a/gm/patheffects.cpp b/gm/patheffects.cpp
index c71d32bb75..517d02e547 100644
--- a/gm/patheffects.cpp
+++ b/gm/patheffects.cpp
@@ -79,7 +79,7 @@ static const PE_Proc gPE[] = { hair_pe, hair2_pe, stroke_pe, dash_pe, one_d_pe }
 
 static void fill_pe(SkPaint* paint) {
     paint->setStyle(SkPaint::kFill_Style);
-    paint->setPathEffect(NULL);
+    paint->setPathEffect(nullptr);
 }
 
 static void discrete_pe(SkPaint* paint) {
diff --git a/gm/pathfill.cpp b/gm/pathfill.cpp
index a2b1ee0142..f4e42e8165 100644
--- a/gm/pathfill.cpp
+++ b/gm/pathfill.cpp
@@ -198,7 +198,7 @@ protected:
                 canvas->save();
                 canvas->clipRect(clipR);
 
-                const SkRect* clipPtr = doclip ? &clipR : NULL;
+                const SkRect* clipPtr = doclip ? &clipR : nullptr;
 
                 show(canvas, path, paint, clipPtr, clipR.fTop, clipR.centerY());
                 show(canvas, path, paint, clipPtr, clipR.centerY(), clipR.fBottom);
diff --git a/gm/pathopsskpclip.cpp b/gm/pathopsskpclip.cpp
index c9092f4ad2..1c8cf99cb8 100644
--- a/gm/pathopsskpclip.cpp
+++ b/gm/pathopsskpclip.cpp
@@ -34,7 +34,7 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         SkPictureRecorder recorder;
-        SkCanvas* rec = recorder.beginRecording(1200, 900, NULL, 0);
+        SkCanvas* rec = recorder.beginRecording(1200, 900, nullptr, 0);
         SkPath p;
         SkRect r = {
             SkIntToScalar(100),
diff --git a/gm/peekpixels.cpp b/gm/peekpixels.cpp
index b8c1678c03..a443c41b89 100644
--- a/gm/peekpixels.cpp
+++ b/gm/peekpixels.cpp
@@ -47,7 +47,7 @@ protected:
                 size_t rowBytes;
                 const void* addr = surfCanvas->peekPixels(&info, &rowBytes);
                 if (addr && bitmap.installPixels(info, const_cast<void*>(addr), rowBytes)) {
-                    canvas->drawBitmap(bitmap, 0, 0, NULL);
+                    canvas->drawBitmap(bitmap, 0, 0, nullptr);
                 }
             }
 
@@ -55,12 +55,12 @@ protected:
             canvas->translate(120, 0);
             SkAutoROCanvasPixels ropixels(surfCanvas);
             if (ropixels.asROBitmap(&bitmap)) {
-                canvas->drawBitmap(bitmap, 0, 0, NULL);
+                canvas->drawBitmap(bitmap, 0, 0, nullptr);
             }
 
             // test Surface
             canvas->translate(120, 0);
-            surface->draw(canvas, 0, 0, NULL);
+            surface->draw(canvas, 0, 0, nullptr);
         }
     }
 
diff --git a/gm/perlinnoise.cpp b/gm/perlinnoise.cpp
index 702e545c60..e4c559801b 100644
--- a/gm/perlinnoise.cpp
+++ b/gm/perlinnoise.cpp
@@ -39,9 +39,9 @@ protected:
         SkISize tileSize = SkISize::Make(fSize.width() / 2, fSize.height() / 2);
         SkShader* shader = (type == SkPerlinNoiseShader::kFractalNoise_Type) ?
             SkPerlinNoiseShader::CreateFractalNoise(baseFrequencyX, baseFrequencyY, numOctaves,
-                                                   seed, stitchTiles ? &tileSize : NULL) :
+                                                   seed, stitchTiles ? &tileSize : nullptr) :
             SkPerlinNoiseShader::CreateTurbulence(baseFrequencyX, baseFrequencyY, numOctaves,
-                                                seed, stitchTiles ? &tileSize : NULL);
+                                                seed, stitchTiles ? &tileSize : nullptr);
         SkPaint paint;
         paint.setShader(shader)->unref();
         if (stitchTiles) {
@@ -112,9 +112,9 @@ protected:
               bool stitchTiles) {
         SkShader* shader = (type == SkPerlinNoiseShader::kFractalNoise_Type) ?
         SkPerlinNoiseShader::CreateFractalNoise(baseFrequencyX, baseFrequencyY, numOctaves,
-                                                seed, stitchTiles ? &fSize : NULL) :
+                                                seed, stitchTiles ? &fSize : nullptr) :
         SkPerlinNoiseShader::CreateTurbulence(baseFrequencyX, baseFrequencyY, numOctaves,
-                                              seed, stitchTiles ? &fSize : NULL);
+                                              seed, stitchTiles ? &fSize : nullptr);
         paint->setShader(shader)->unref();
     }
 
diff --git a/gm/picture.cpp b/gm/picture.cpp
index 175e0a76f2..1f8ded0bac 100644
--- a/gm/picture.cpp
+++ b/gm/picture.cpp
@@ -40,7 +40,7 @@ static SkPicture* make_picture() {
 class PictureGM : public skiagm::GM {
 public:
     PictureGM()
-        : fPicture(NULL)
+        : fPicture(nullptr)
     {}
 
 protected:
@@ -65,7 +65,7 @@ protected:
         canvas->drawPicture(fPicture);
         
         matrix.setTranslate(110, 0);
-        canvas->drawPicture(fPicture, &matrix, NULL);
+        canvas->drawPicture(fPicture, &matrix, nullptr);
         
         matrix.postTranslate(110, 0);
         canvas->drawPicture(fPicture, &matrix, &paint);
diff --git a/gm/pictureimagefilter.cpp b/gm/pictureimagefilter.cpp
index fd8ae62fa2..7f6cfbdd9a 100644
--- a/gm/pictureimagefilter.cpp
+++ b/gm/pictureimagefilter.cpp
@@ -24,7 +24,7 @@ protected:
 
     void makePicture() {
         SkPictureRecorder recorder;
-        SkCanvas* canvas = recorder.beginRecording(100, 100, NULL, 0);
+        SkCanvas* canvas = recorder.beginRecording(100, 100, nullptr, 0);
         canvas->clear(SK_ColorBLACK);
         SkPaint paint;
         paint.setAntiAlias(true);
diff --git a/gm/pictureshader.cpp b/gm/pictureshader.cpp
index d28749a644..c35c5c964e 100644
--- a/gm/pictureshader.cpp
+++ b/gm/pictureshader.cpp
@@ -33,7 +33,7 @@ public:
     void onOnceBeforeDraw() override {
        // Build the picture.
         SkPictureRecorder recorder;
-        SkCanvas* pictureCanvas = recorder.beginRecording(fTileSize, fTileSize, NULL, 0);
+        SkCanvas* pictureCanvas = recorder.beginRecording(fTileSize, fTileSize, nullptr, 0);
         this->drawTile(pictureCanvas);
         fPicture.reset(recorder.endRecording());
 
@@ -150,12 +150,9 @@ private:
         canvas->drawRect(SkRect::MakeWH(fSceneSize, fSceneSize), paint);
         canvas->drawRect(SkRect::MakeXYWH(fSceneSize * 1.1f, 0, fSceneSize, fSceneSize), paint);
 
-        SkAutoTUnref<SkShader> pictureShader(SkShader::CreatePictureShader(
-                    fPicture,
-                    kTileConfigs[tileMode].tmx,
-                    kTileConfigs[tileMode].tmy,
-                    &localMatrix,
-                    NULL));
+        SkAutoTUnref<SkShader> pictureShader(
+                SkShader::CreatePictureShader(fPicture, kTileConfigs[tileMode].tmx,
+                                              kTileConfigs[tileMode].tmy, &localMatrix, nullptr));
         paint.setShader(pictureShader.get());
         canvas->drawRect(SkRect::MakeWH(fSceneSize, fSceneSize), paint);
 
@@ -200,12 +197,9 @@ DEF_SIMPLE_GM(tiled_picture_shader, canvas, 400, 400) {
     c->drawLine(20, 20, 80, 80, p);
 
     SkAutoTUnref<SkPicture> picture(recorder.endRecording());
-    SkAutoTUnref<SkShader> shader(SkShader::CreatePictureShader(
-	      picture.get(),
-	      SkShader::kRepeat_TileMode,
-	      SkShader::kRepeat_TileMode,
-	      NULL,
-	      NULL));
+    SkAutoTUnref<SkShader> shader(
+            SkShader::CreatePictureShader(picture.get(), SkShader::kRepeat_TileMode,
+                                          SkShader::kRepeat_TileMode, nullptr, nullptr));
 
     p.setColor(sk_tool_utils::color_to_565(0xFF8BC34A));  // green
     canvas->drawPaint(p);
diff --git a/gm/pictureshadertile.cpp b/gm/pictureshadertile.cpp
index a84e23343d..30776c338b 100644
--- a/gm/pictureshadertile.cpp
+++ b/gm/pictureshadertile.cpp
@@ -121,7 +121,7 @@ protected:
             if (tile == SkRect::MakeWH(kPictureSize, kPictureSize)) {
                 // When the tile == picture bounds, exercise the picture + offset path.
                 picturePtr = offsetPicture.get();
-                tilePtr = NULL;
+                tilePtr = nullptr;
             }
 
             fShaders[i].reset(SkShader::CreatePictureShader(picturePtr,
diff --git a/gm/resizeimagefilter.cpp b/gm/resizeimagefilter.cpp
index 4a6da53c97..ca7f554fdb 100644
--- a/gm/resizeimagefilter.cpp
+++ b/gm/resizeimagefilter.cpp
@@ -27,7 +27,7 @@ protected:
               const SkRect& rect,
               const SkSize& deviceSize,
               SkFilterQuality filterQuality,
-              SkImageFilter* input = NULL) {
+              SkImageFilter* input = nullptr) {
         SkRect dstRect;
         canvas->getTotalMatrix().mapRect(&dstRect, rect);
         canvas->save();
diff --git a/gm/roundrects.cpp b/gm/roundrects.cpp
index b27d0f4309..ab7ee696c2 100644
--- a/gm/roundrects.cpp
+++ b/gm/roundrects.cpp
@@ -282,7 +282,7 @@ protected:
             canvas->drawRect(rect, rectPaint);
             canvas->drawRRect(circleRect, fPaints[i]);
 
-            fPaints[i].setShader(NULL);
+            fPaints[i].setShader(nullptr);
 
             canvas->restore();
         }
diff --git a/gm/rrects.cpp b/gm/rrects.cpp
index f9a21db0f2..c4736c7222 100644
--- a/gm/rrects.cpp
+++ b/gm/rrects.cpp
@@ -57,12 +57,12 @@ protected:
     SkISize onISize() override { return SkISize::Make(kImageWidth, kImageHeight); }
 
     void onDraw(SkCanvas* canvas) override {
-        GrContext* context = NULL;
+        GrContext* context = nullptr;
 #if SK_SUPPORT_GPU
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        context = rt ? rt->getContext() : NULL;
+        context = rt ? rt->getContext() : nullptr;
 #endif
-        if (kEffect_Type == fType && NULL == context) {
+        if (kEffect_Type == fType && nullptr == context) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
@@ -102,7 +102,7 @@ protected:
 #if SK_SUPPORT_GPU
                         GrTestTarget tt;
                         context->getTestTarget(&tt);
-                        if (NULL == tt.target()) {
+                        if (nullptr == tt.target()) {
                             SkDEBUGFAIL("Couldn't get Gr test target.");
                             return;
                         }
diff --git a/gm/samplerstress.cpp b/gm/samplerstress.cpp
index eff6281cdd..4bec6784a8 100644
--- a/gm/samplerstress.cpp
+++ b/gm/samplerstress.cpp
@@ -21,8 +21,8 @@ class SamplerStressGM : public GM {
 public:
     SamplerStressGM()
     : fTextureCreated(false)
-    , fShader(NULL)
-    , fMaskFilter(NULL) {
+    , fShader(nullptr)
+    , fMaskFilter(nullptr) {
     }
 
     virtual ~SamplerStressGM() {
diff --git a/gm/shaderbounds.cpp b/gm/shaderbounds.cpp
index 4363d4eee3..fd42973dba 100644
--- a/gm/shaderbounds.cpp
+++ b/gm/shaderbounds.cpp
@@ -18,7 +18,7 @@ static SkShader* MakeLinear(SkScalar width, SkScalar height, bool alternate,
     colors[0] = SK_ColorBLUE;
     colors[1] = SK_ColorYELLOW;
   }
-  return SkGradientShader::CreateLinear(pts, colors, NULL, 2,
+  return SkGradientShader::CreateLinear(pts, colors, nullptr, 2,
                                         SkShader::kClamp_TileMode, 0, &localMatrix);
 }
 
diff --git a/gm/shadertext.cpp b/gm/shadertext.cpp
index fd74e7c6ce..e68ee98df0 100644
--- a/gm/shadertext.cpp
+++ b/gm/shadertext.cpp
@@ -42,8 +42,8 @@ static const SkColor gColors[] = {
 };
 
 static const GradData gGradData[] = {
-    { 2, gColors, NULL },
-    { 5, gColors, NULL },
+    { 2, gColors, nullptr },
+    { 5, gColors, nullptr },
 };
 
 static SkShader* MakeLinear(const SkPoint pts[2], const GradData& data, SkShader::TileMode tm) {
@@ -174,7 +174,7 @@ protected:
             ++i;
             canvas->translate(SkIntToScalar((i / testsPerCol) * colWidth),
                               SkIntToScalar((i % testsPerCol) * rowHeight));
-            canvas->drawTextOnPath(text, textLen, path, NULL, paint);
+            canvas->drawTextOnPath(text, textLen, path, nullptr, paint);
             canvas->restore();
         }
         canvas->restore();
diff --git a/gm/shadertext2.cpp b/gm/shadertext2.cpp
index f4af684ae9..8ceb5e494b 100644
--- a/gm/shadertext2.cpp
+++ b/gm/shadertext2.cpp
@@ -175,8 +175,8 @@ protected:
 
                     canvas->save();
                         canvas->concat(matrices[m].fMatrix);
-                        canvas->drawTextOnPath(kText, kTextLen, path, NULL, paint);
-                        canvas->drawTextOnPath(kText, kTextLen, path, NULL, outlinePaint);
+                        canvas->drawTextOnPath(kText, kTextLen, path, nullptr, paint);
+                        canvas->drawTextOnPath(kText, kTextLen, path, nullptr, outlinePaint);
                     canvas->restore();
                     SkPaint stroke;
                     stroke.setStyle(SkPaint::kStroke_Style);
diff --git a/gm/shallowgradient.cpp b/gm/shallowgradient.cpp
index 276ec14f49..b2a34f3b4c 100644
--- a/gm/shallowgradient.cpp
+++ b/gm/shallowgradient.cpp
@@ -12,13 +12,13 @@ typedef SkShader* (*MakeShaderProc)(const SkColor[], int count, const SkSize&);
 
 static SkShader* shader_linear(const SkColor colors[], int count, const SkSize& size) {
     SkPoint pts[] = { { 0, 0 }, { size.width(), size.height() } };
-    return SkGradientShader::CreateLinear(pts, colors, NULL, count,
+    return SkGradientShader::CreateLinear(pts, colors, nullptr, count,
                                           SkShader::kClamp_TileMode);
 }
 
 static SkShader* shader_radial(const SkColor colors[], int count, const SkSize& size) {
     SkPoint center = { size.width()/2, size.height()/2 };
-    return SkGradientShader::CreateRadial(center, size.width()/2, colors, NULL, count,
+    return SkGradientShader::CreateRadial(center, size.width()/2, colors, nullptr, count,
                                           SkShader::kClamp_TileMode);
 }
 
@@ -26,13 +26,13 @@ static SkShader* shader_conical(const SkColor colors[], int count, const SkSize&
     SkPoint center = { size.width()/2, size.height()/2 };
     return SkGradientShader::CreateTwoPointConical(center, size.width()/64,
                                                    center, size.width()/2,
-                                                   colors, NULL, count,
+                                                   colors, nullptr, count,
                                                    SkShader::kClamp_TileMode);
 }
 
 static SkShader* shader_sweep(const SkColor colors[], int count, const SkSize& size) {
     return SkGradientShader::CreateSweep(size.width()/2, size.height()/2,
-                                         colors, NULL, count);
+                                         colors, nullptr, count);
 }
 
 class ShallowGradientGM : public skiagm::GM {
diff --git a/gm/simpleaaclip.cpp b/gm/simpleaaclip.cpp
index 372cb1bafb..3b10c47ea0 100644
--- a/gm/simpleaaclip.cpp
+++ b/gm/simpleaaclip.cpp
@@ -68,10 +68,10 @@ protected:
     }
 
     void buildRgn(SkAAClip* clip, SkRegion::Op op) {
-        clip->setPath(fBasePath, NULL, true);
+        clip->setPath(fBasePath, nullptr, true);
 
         SkAAClip clip2;
-        clip2.setPath(fRectPath, NULL, true);
+        clip2.setPath(fRectPath, nullptr, true);
         clip->op(clip2, op);
     }
 
diff --git a/gm/spritebitmap.cpp b/gm/spritebitmap.cpp
index 9e1bb87810..ceed50acaa 100644
--- a/gm/spritebitmap.cpp
+++ b/gm/spritebitmap.cpp
@@ -23,7 +23,7 @@ static void make_bm(SkBitmap* bm) {
 }
 
 static void draw_2_bitmaps(SkCanvas* canvas, const SkBitmap& bm, bool doClip,
-                           int dx, int dy, SkImageFilter* filter = NULL) {
+                           int dx, int dy, SkImageFilter* filter = nullptr) {
     SkAutoCanvasRestore acr(canvas, true);
     SkPaint paint;
 
diff --git a/gm/srcmode.cpp b/gm/srcmode.cpp
index 7a7e89e052..86fe89bd1a 100644
--- a/gm/srcmode.cpp
+++ b/gm/srcmode.cpp
@@ -21,13 +21,13 @@
 typedef void (*PaintProc)(SkPaint*);
 
 static void identity_paintproc(SkPaint* paint) {
-    paint->setShader(NULL);
+    paint->setShader(nullptr);
 }
 
 static void gradient_paintproc(SkPaint* paint) {
     const SkColor colors[] = { SK_ColorGREEN, SK_ColorBLUE };
     const SkPoint pts[] = { { 0, 0 }, { W, H } };
-    SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL,
+    SkShader* s = SkGradientShader::CreateLinear(pts, colors, nullptr,
                                                  SK_ARRAY_COUNT(colors),
                                                  SkShader::kClamp_TileMode);
     paint->setShader(s)->unref();
@@ -126,8 +126,8 @@ protected:
             callNewSurface = false;
         }
 #endif
-        SkSurface* surface = callNewSurface ? canvas->newSurface(info) : NULL;
-        if (NULL == surface) {
+        SkSurface* surface = callNewSurface ? canvas->newSurface(info) : nullptr;
+        if (nullptr == surface) {
             // picture canvas will return null, so fall-back to raster
             surface = SkSurface::NewRaster(info);
         }
@@ -139,7 +139,7 @@ protected:
                                                     this->isCanvasDeferred()));
         surf->getCanvas()->drawColor(SK_ColorWHITE);
         this->drawContent(surf->getCanvas());
-        surf->draw(canvas, 0, 0, NULL);
+        surf->draw(canvas, 0, 0, nullptr);
     }
 
 private:
diff --git a/gm/strokefill.cpp b/gm/strokefill.cpp
index 4e8eaffcca..e8878b5e3b 100644
--- a/gm/strokefill.cpp
+++ b/gm/strokefill.cpp
@@ -307,7 +307,7 @@ protected:
         SkASSERT(SkPathPriv::CheapIsFirstDirection(path2, SkPathPriv::kCCW_FirstDirection));
 
         path2.reset();
-        SkASSERT(!SkPathPriv::CheapComputeFirstDirection(path2, NULL));
+        SkASSERT(!SkPathPriv::CheapComputeFirstDirection(path2, nullptr));
         path2.addCircle(x + SkIntToScalar(360), y + SkIntToScalar(200), SkIntToScalar(50), SkPath::kCW_Direction);
         SkASSERT(SkPathPriv::CheapIsFirstDirection(path2, SkPathPriv::kCW_FirstDirection));
         canvas->drawPath(path2, paint);
@@ -333,7 +333,7 @@ protected:
         r = SkRect::MakeXYWH(x + SkIntToScalar(190), y + SkIntToScalar(280), 
                              SkIntToScalar(100), SkIntToScalar(100));
         path4.reset();
-        SkASSERT(!SkPathPriv::CheapComputeFirstDirection(path4, NULL));
+        SkASSERT(!SkPathPriv::CheapComputeFirstDirection(path4, nullptr));
         path4.addRect(r, SkPath::kCCW_Direction);
         SkASSERT(SkPathPriv::CheapIsFirstDirection(path4, SkPathPriv::kCCW_FirstDirection));
         path4.moveTo(0, 0); // test for crbug.com/247770
@@ -342,7 +342,7 @@ protected:
         r = SkRect::MakeXYWH(x + SkIntToScalar(310), y + SkIntToScalar(280), 
                              SkIntToScalar(100), SkIntToScalar(100));
         path4.reset();
-        SkASSERT(!SkPathPriv::CheapComputeFirstDirection(path4, NULL));
+        SkASSERT(!SkPathPriv::CheapComputeFirstDirection(path4, nullptr));
         path4.addRect(r, SkPath::kCW_Direction);
         SkASSERT(SkPathPriv::CheapIsFirstDirection(path4, SkPathPriv::kCW_FirstDirection));
         path4.moveTo(0, 0); // test for crbug.com/247770
diff --git a/gm/surface.cpp b/gm/surface.cpp
index 694a0d09ab..bf7f931f46 100644
--- a/gm/surface.cpp
+++ b/gm/surface.cpp
@@ -18,7 +18,7 @@ static SkShader* make_shader() {
     int b = 0xBB;
     SkPoint pts[] = { { 0, 0 }, { W, H } };
     SkColor colors[] = { SkColorSetRGB(a, a, a), SkColorSetRGB(b, b, b) };
-    return SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
+    return SkGradientShader::CreateLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
 }
 
 static SkSurface* make_surface(GrContext* ctx, const SkImageInfo& info, SkPixelGeometry geo,
@@ -48,7 +48,7 @@ static void test_draw(SkCanvas* canvas, const char label[]) {
 
     paint.setShader(make_shader())->unref();
     canvas->drawRect(SkRect::MakeWH(W, H), paint);
-    paint.setShader(NULL);
+    paint.setShader(nullptr);
 
     paint.setColor(SK_ColorWHITE);
     paint.setTextSize(32);
@@ -95,7 +95,7 @@ protected:
                     SkAutoTUnref<SkSurface> surface(make_surface(ctx, info, rec[i].fGeo,
                                                                  disallowAA, disallowDither));
                     test_draw(surface->getCanvas(), rec[i].fLabel);
-                    surface->draw(canvas, x, y, NULL);
+                    surface->draw(canvas, x, y, nullptr);
                     y += H;
                 }
                 x += W;
@@ -134,23 +134,23 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         SkImageInfo info = SkImageInfo::MakeN32Premul(100, 100);
 
-        SkAutoTUnref<SkSurface> surf(canvas->newSurface(info, NULL));
+        SkAutoTUnref<SkSurface> surf(canvas->newSurface(info, nullptr));
         if (!surf.get()) {
             surf.reset(SkSurface::NewRaster(info));
         }
         drawInto(surf->getCanvas());
 
         SkAutoTUnref<SkImage> image(surf->newImageSnapshot());
-        canvas->drawImage(image, 10, 10, NULL);
+        canvas->drawImage(image, 10, 10, nullptr);
 
-        SkAutoTUnref<SkSurface> surf2(image->newSurface(info, NULL));
+        SkAutoTUnref<SkSurface> surf2(image->newSurface(info, nullptr));
         drawInto(surf2->getCanvas());
 
         // Assert that the props were communicated transitively through the first image
         SkASSERT(equal(surf->props(), surf2->props()));
 
         SkAutoTUnref<SkImage> image2(surf2->newImageSnapshot());
-        canvas->drawImage(image2, 10 + SkIntToScalar(image->width()) + 10, 10, NULL);
+        canvas->drawImage(image2, 10 + SkIntToScalar(image->width()) + 10, 10, nullptr);
     }
 
 private:
diff --git a/gm/tablecolorfilter.cpp b/gm/tablecolorfilter.cpp
index 0855ac0ea3..1053bb2518 100644
--- a/gm/tablecolorfilter.cpp
+++ b/gm/tablecolorfilter.cpp
@@ -17,7 +17,7 @@ static SkShader* make_shader0(int w, int h) {
         SK_ColorBLACK, SK_ColorGREEN, SK_ColorCYAN,
         SK_ColorRED, 0, SK_ColorBLUE, SK_ColorWHITE
     };
-    return SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
+    return SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
                                           SkShader::kClamp_TileMode);
 }
 static void make_bm0(SkBitmap* bm) {
@@ -37,7 +37,7 @@ static SkShader* make_shader1(int w, int h) {
     SkColor colors[] = {
         SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE,
     };
-    return SkGradientShader::CreateRadial(SkPoint::Make(cx, cy), cx, colors, NULL,
+    return SkGradientShader::CreateRadial(SkPoint::Make(cx, cy), cx, colors, nullptr,
                                           SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode);
 }
 static void make_bm1(SkBitmap* bm) {
@@ -74,7 +74,7 @@ static void make_table2(uint8_t table[]) {
 }
 
 static SkColorFilter* make_null_cf() {
-    return NULL;
+    return nullptr;
 }
 
 static SkColorFilter* make_cf0() {
@@ -93,7 +93,7 @@ static SkColorFilter* make_cf3() {
     uint8_t table0[256]; make_table0(table0);
     uint8_t table1[256]; make_table1(table1);
     uint8_t table2[256]; make_table2(table2);
-    return SkTableColorFilter::CreateARGB(NULL, table0, table1, table2);
+    return SkTableColorFilter::CreateARGB(nullptr, table0, table1, table2);
 }
 
 class TableColorFilterGM : public skiagm::GM {
@@ -159,12 +159,12 @@ protected:
                 canvas->drawBitmap(bm, x, y, &paint);
             }
 
-            paint.setColorFilter(NULL);
+            paint.setColorFilter(nullptr);
 
             for (unsigned i = 0; i < SK_ARRAY_COUNT(gColorFilterMakers); ++i) {
                 SkAutoTUnref<SkColorFilter> colorFilter1(gColorFilterMakers[i]());
                 SkAutoTUnref<SkImageFilter> imageFilter1(SkColorFilterImageFilter::Create(
-                            colorFilter1, NULL, NULL));
+                            colorFilter1, nullptr, nullptr));
 
                 // Move down to the next line and draw it
                 // each draw being at xOffset of the previous one
@@ -173,7 +173,7 @@ protected:
                 for (unsigned j = 1; j < SK_ARRAY_COUNT(gColorFilterMakers); ++j) {
                     SkAutoTUnref<SkColorFilter> colorFilter2(gColorFilterMakers[j]());
                     SkAutoTUnref<SkImageFilter> imageFilter2(SkColorFilterImageFilter::Create(
-                                colorFilter2, imageFilter1, NULL));
+                                colorFilter2, imageFilter1, nullptr));
                     paint.setImageFilter(imageFilter2);
                     canvas->drawBitmap(bm, x, y, &paint);
                     x += xOffset;
diff --git a/gm/texdata.cpp b/gm/texdata.cpp
index e7c15b2498..13a1c2a6c2 100644
--- a/gm/texdata.cpp
+++ b/gm/texdata.cpp
@@ -39,7 +39,7 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* target = canvas->internal_private_accessTopLayerRenderTarget();
         GrContext* ctx = canvas->getGrContext();
-        GrDrawContext* drawContext = ctx ? ctx->drawContext() : NULL;
+        GrDrawContext* drawContext = ctx ? ctx->drawContext() : nullptr;
         if (drawContext && target) {
             SkAutoTArray<SkPMColor> gTextureData((2 * S) * (2 * S));
             static const int stride = 2 * S;
diff --git a/gm/textblob.cpp b/gm/textblob.cpp
index 5020e7c5ef..a38215653d 100644
--- a/gm/textblob.cpp
+++ b/gm/textblob.cpp
@@ -76,7 +76,7 @@ protected:
         SkPaint p;
         p.setTypeface(fTypeface);
         size_t txtLen = strlen(fText);
-        int glyphCount = p.textToGlyphs(fText, txtLen, NULL);
+        int glyphCount = p.textToGlyphs(fText, txtLen, nullptr);
 
         fGlyphs.append(glyphCount);
         p.textToGlyphs(fText, txtLen, fGlyphs.begin());
diff --git a/gm/textbloblooper.cpp b/gm/textbloblooper.cpp
index dc4be0b129..c40a4eb2c6 100644
--- a/gm/textbloblooper.cpp
+++ b/gm/textbloblooper.cpp
@@ -30,7 +30,7 @@ static void add_to_text_blob(SkTextBlobBuilder* builder, const char* text, const
     SkTDArray<uint16_t> glyphs;
 
     size_t len = strlen(text);
-    glyphs.append(paint.textToGlyphs(text, len, NULL));
+    glyphs.append(paint.textToGlyphs(text, len, nullptr));
     paint.textToGlyphs(text, len, glyphs.begin());
 
     const SkScalar advanceX = paint.getTextSize() * 0.85f;
@@ -90,7 +90,7 @@ static SkShader* make_shader(const SkRect& bounds) {
         SK_ColorCYAN, SK_ColorMAGENTA, SK_ColorYELLOW,
     };
     return SkGradientShader::CreateLinear(pts,
-                                          colors, NULL, SK_ARRAY_COUNT(colors),
+                                          colors, nullptr, SK_ARRAY_COUNT(colors),
                                           SkShader::kClamp_TileMode);
 }
 
@@ -202,7 +202,7 @@ protected:
                                                SkLayerDrawLooper::kColorFilter_Bit |
                                                SkLayerDrawLooper::kXfermode_Bit, &color_filter,
                                                xfermode, SK_ARRAY_COUNT(xfermode)));
-        fLoopers.push_back().reset(setupLooper(0, NULL, skew, SK_ARRAY_COUNT(skew)));
+        fLoopers.push_back().reset(setupLooper(0, nullptr, skew, SK_ARRAY_COUNT(skew)));
         fLoopers.push_back().reset(setupLooper(SkLayerDrawLooper::kMaskFilter_Bit |
                                                SkLayerDrawLooper::kShader_Bit |
                                                SkLayerDrawLooper::kColorFilter_Bit |
diff --git a/gm/textblobmixedsizes.cpp b/gm/textblobmixedsizes.cpp
index a76c6f575b..9f745d6106 100644
--- a/gm/textblobmixedsizes.cpp
+++ b/gm/textblobmixedsizes.cpp
@@ -165,7 +165,7 @@ protected:
             // since we prepended this matrix already, we blit using identity
             inputCanvas->resetMatrix();
             SkImage* image = surface->newImageSnapshot();
-            inputCanvas->drawImage(image, 0, 0, NULL);
+            inputCanvas->drawImage(image, 0, 0, nullptr);
             image->unref();
         }
 #endif
diff --git a/gm/textblobrandomfont.cpp b/gm/textblobrandomfont.cpp
index ada46cadfc..862d83b707 100644
--- a/gm/textblobrandomfont.cpp
+++ b/gm/textblobrandomfont.cpp
@@ -41,7 +41,7 @@ protected:
         // Setup our random scaler context
         SkAutoTUnref<SkTypeface> orig(sk_tool_utils::create_portable_typeface("sans-serif",
                                                                               SkTypeface::kBold));
-        if (NULL == orig) {
+        if (nullptr == orig) {
             orig.reset(SkTypeface::RefDefault());
         }
         SkAutoTUnref<SkTypeface> random(new SkRandomTypeface(orig, paint, false));
@@ -93,7 +93,7 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         // This GM exists to test a specific feature of the GPU backend.
-        if (NULL == canvas->getGrContext()) {
+        if (nullptr == canvas->getGrContext()) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
diff --git a/gm/textblobshader.cpp b/gm/textblobshader.cpp
index 5c9372d93c..30674e1d68 100644
--- a/gm/textblobshader.cpp
+++ b/gm/textblobshader.cpp
@@ -22,7 +22,7 @@ public:
         SkPaint p;
         sk_tool_utils::set_portable_typeface(&p);
         size_t txtLen = strlen(txt);
-        fGlyphs.append(p.textToGlyphs(txt, txtLen, NULL));
+        fGlyphs.append(p.textToGlyphs(txt, txtLen, nullptr));
         p.textToGlyphs(txt, txtLen, fGlyphs.begin());
     }
 
@@ -40,16 +40,16 @@ protected:
         int glyphCount = fGlyphs.count();
         const SkTextBlobBuilder::RunBuffer* run;
 
-        run = &builder.allocRun(p, glyphCount, 10, 10, NULL);
+        run = &builder.allocRun(p, glyphCount, 10, 10, nullptr);
         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
 
-        run = &builder.allocRunPosH(p, glyphCount,  80, NULL);
+        run = &builder.allocRunPosH(p, glyphCount,  80, nullptr);
         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
         for (int i = 0; i < glyphCount; ++i) {
             run->pos[i] = p.getTextSize() * i * .75f;
         }
 
-        run = &builder.allocRunPos(p, glyphCount, NULL);
+        run = &builder.allocRunPos(p, glyphCount, nullptr);
         memcpy(run->glyphs, fGlyphs.begin(), glyphCount * sizeof(uint16_t));
         for (int i = 0; i < glyphCount; ++i) {
             run->pos[i * 2] = p.getTextSize() * i * .75f;
diff --git a/gm/textblobuseaftergpufree.cpp b/gm/textblobuseaftergpufree.cpp
index 363cd2fed9..91681b82ac 100644
--- a/gm/textblobuseaftergpufree.cpp
+++ b/gm/textblobuseaftergpufree.cpp
@@ -31,7 +31,7 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         // This GM exists to test a specific feature of the GPU backend.
-        if (NULL == canvas->getGrContext()) {
+        if (nullptr == canvas->getGrContext()) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
diff --git a/gm/texteffects.cpp b/gm/texteffects.cpp
index 03dbd68cc1..902bed3ea8 100644
--- a/gm/texteffects.cpp
+++ b/gm/texteffects.cpp
@@ -17,7 +17,7 @@ static void r0(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
                               SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(3))))->unref();
     rastBuilder->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));
 
-    p.setMaskFilter(NULL);
+    p.setMaskFilter(nullptr);
     p.setStyle(SkPaint::kStroke_Style);
     p.setStrokeWidth(SK_Scalar1);
     rastBuilder->addLayer(p);
@@ -68,7 +68,7 @@ static void r4(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
     p.setXfermodeMode(SkXfermode::kClear_Mode);
     rastBuilder->addLayer(p, SK_Scalar1*3/2, SK_Scalar1*3/2);
 
-    p.setXfermode(NULL);
+    p.setXfermode(nullptr);
     rastBuilder->addLayer(p);
 }
 
@@ -119,8 +119,8 @@ static void r8(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
     p.setXfermodeMode(SkXfermode::kClear_Mode);
     rastBuilder->addLayer(p);
 
-    p.setPathEffect(NULL);
-    p.setXfermode(NULL);
+    p.setPathEffect(nullptr);
+    p.setXfermode(nullptr);
     p.setStyle(SkPaint::kStroke_Style);
     p.setStrokeWidth(SK_Scalar1);
     rastBuilder->addLayer(p);
@@ -136,8 +136,8 @@ static void r9(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
     p.setXfermodeMode(SkXfermode::kClear_Mode);
     rastBuilder->addLayer(p);
 
-    p.setPathEffect(NULL);
-    p.setXfermode(NULL);
+    p.setPathEffect(nullptr);
+    p.setXfermode(nullptr);
     p.setStyle(SkPaint::kStroke_Style);
     p.setStrokeWidth(SK_Scalar1);
     rastBuilder->addLayer(p);
@@ -199,7 +199,7 @@ protected:
         for (int i = 0; i < static_cast<int>(SK_ARRAY_COUNT(gRastProcs)); i++) {
             apply_shader(&paint, i);
 
-            //  paint.setMaskFilter(NULL);
+            //  paint.setMaskFilter(nullptr);
             //  paint.setColor(SK_ColorBLACK);
 
             canvas->drawText(str.c_str(), str.size(), x, y, paint);
diff --git a/gm/texturedomaineffect.cpp b/gm/texturedomaineffect.cpp
index eb0f2cc944..facfb7a792 100644
--- a/gm/texturedomaineffect.cpp
+++ b/gm/texturedomaineffect.cpp
@@ -49,19 +49,19 @@ protected:
 
         SkColor colors1[] = { SK_ColorCYAN, SK_ColorLTGRAY, SK_ColorGRAY };
         paint.setShader(SkGradientShader::CreateSweep(65.f, 75.f, colors1,
-                                                      NULL, SK_ARRAY_COUNT(colors1)))->unref();
+                                                      nullptr, SK_ARRAY_COUNT(colors1)))->unref();
         canvas.drawOval(SkRect::MakeXYWH(-5.f, -5.f,
                                          fBmp.width() + 10.f, fBmp.height() + 10.f), paint);
 
         SkColor colors2[] = { SK_ColorMAGENTA, SK_ColorLTGRAY, SK_ColorYELLOW };
-        paint.setShader(SkGradientShader::CreateSweep(45.f, 55.f, colors2, NULL,
+        paint.setShader(SkGradientShader::CreateSweep(45.f, 55.f, colors2, nullptr,
                                                       SK_ARRAY_COUNT(colors2)))->unref();
         paint.setXfermodeMode(SkXfermode::kDarken_Mode);
         canvas.drawOval(SkRect::MakeXYWH(-5.f, -5.f,
                                          fBmp.width() + 10.f, fBmp.height() + 10.f), paint);
 
         SkColor colors3[] = { SK_ColorBLUE, SK_ColorLTGRAY, SK_ColorGREEN };
-        paint.setShader(SkGradientShader::CreateSweep(25.f, 35.f, colors3, NULL,
+        paint.setShader(SkGradientShader::CreateSweep(25.f, 35.f, colors3, nullptr,
                                                       SK_ARRAY_COUNT(colors3)))->unref();
         paint.setXfermodeMode(SkXfermode::kLighten_Mode);
         canvas.drawOval(SkRect::MakeXYWH(-5.f, -5.f,
@@ -70,23 +70,23 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        if (NULL == rt) {
+        if (nullptr == rt) {
             return;
         }
         GrContext* context = rt->getContext();
-        if (NULL == context) {
+        if (nullptr == context) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
 
         GrTestTarget tt;
         context->getTestTarget(&tt);
-        if (NULL == tt.target()) {
+        if (nullptr == tt.target()) {
             SkDEBUGFAIL("Couldn't get Gr test target.");
             return;
         }
 
-        SkAutoTUnref<GrTexture> texture(GrRefCachedBitmapTexture(context, fBmp, NULL));
+        SkAutoTUnref<GrTexture> texture(GrRefCachedBitmapTexture(context, fBmp, nullptr));
         if (!texture) {
             return;
         }
diff --git a/gm/tileimagefilter.cpp b/gm/tileimagefilter.cpp
index 1ec05113e1..e47e8fa659 100644
--- a/gm/tileimagefilter.cpp
+++ b/gm/tileimagefilter.cpp
@@ -98,7 +98,7 @@ protected:
                                         SkIntToScalar(fBitmap.height()));
         SkRect dstRect = SkRect::MakeWH(SkIntToScalar(fBitmap.width() * 2),
                                         SkIntToScalar(fBitmap.height() * 2));
-        SkAutoTUnref<SkImageFilter> tile(SkTileImageFilter::Create(srcRect, dstRect, NULL));
+        SkAutoTUnref<SkImageFilter> tile(SkTileImageFilter::Create(srcRect, dstRect, nullptr));
         SkAutoTUnref<SkColorFilter> cf(SkColorMatrixFilter::Create(matrix));
 
         SkAutoTUnref<SkImageFilter> cfif(SkColorFilterImageFilter::Create(cf, tile.get()));
diff --git a/gm/tilemodes.cpp b/gm/tilemodes.cpp
index 4e4a2ff8ce..26b83486e8 100644
--- a/gm/tilemodes.cpp
+++ b/gm/tilemodes.cpp
@@ -171,14 +171,14 @@ static SkShader* make_grad(SkShader::TileMode tx, SkShader::TileMode ty) {
     int index = (int)ty;
     switch (index % 3) {
         case 0:
-            return SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors), tx);
+            return SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors), tx);
         case 1:
-            return SkGradientShader::CreateRadial(center, rad, colors, NULL, SK_ARRAY_COUNT(colors), tx);
+            return SkGradientShader::CreateRadial(center, rad, colors, nullptr, SK_ARRAY_COUNT(colors), tx);
         case 2:
-            return SkGradientShader::CreateSweep(center.fX, center.fY, colors, NULL, SK_ARRAY_COUNT(colors));
+            return SkGradientShader::CreateSweep(center.fX, center.fY, colors, nullptr, SK_ARRAY_COUNT(colors));
     }
 
-    return NULL;
+    return nullptr;
 }
 
 typedef SkShader* (*ShaderProc)(SkShader::TileMode, SkShader::TileMode);
diff --git a/gm/tilemodes_scaled.cpp b/gm/tilemodes_scaled.cpp
index 87e3029a01..0d46fb66c5 100644
--- a/gm/tilemodes_scaled.cpp
+++ b/gm/tilemodes_scaled.cpp
@@ -175,14 +175,14 @@ static SkShader* make_grad(SkShader::TileMode tx, SkShader::TileMode ty) {
     int index = (int)ty;
     switch (index % 3) {
         case 0:
-            return SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors), tx);
+            return SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors), tx);
         case 1:
-            return SkGradientShader::CreateRadial(center, rad, colors, NULL, SK_ARRAY_COUNT(colors), tx);
+            return SkGradientShader::CreateRadial(center, rad, colors, nullptr, SK_ARRAY_COUNT(colors), tx);
         case 2:
-            return SkGradientShader::CreateSweep(center.fX, center.fY, colors, NULL, SK_ARRAY_COUNT(colors));
+            return SkGradientShader::CreateSweep(center.fX, center.fY, colors, nullptr, SK_ARRAY_COUNT(colors));
     }
 
-    return NULL;
+    return nullptr;
 }
 
 typedef SkShader* (*ShaderProc)(SkShader::TileMode, SkShader::TileMode);
diff --git a/gm/tinybitmap.cpp b/gm/tinybitmap.cpp
index 9bfa2287ca..7942b4266a 100644
--- a/gm/tinybitmap.cpp
+++ b/gm/tinybitmap.cpp
@@ -20,7 +20,7 @@ static SkBitmap make_bitmap() {
     SkBitmap bm;
     bm.allocPixels(SkImageInfo::Make(1, 1, kIndex_8_SkColorType,
                                      kPremul_SkAlphaType),
-                   NULL, ctable);
+                   nullptr, ctable);
     ctable->unref();
 
     bm.lockPixels();
diff --git a/gm/transparency.cpp b/gm/transparency.cpp
index 62c277a691..73bd8b2023 100644
--- a/gm/transparency.cpp
+++ b/gm/transparency.cpp
@@ -32,7 +32,7 @@ static void make_transparency(SkCanvas* canvas,
         shaderColors[0] = SK_AlphaTRANSPARENT;
         shaderColors[1] = kColors[i];
         SkAutoTUnref<SkShader> shader(SkGradientShader::CreateLinear(
-                pts, shaderColors, NULL, 2, SkShader::kClamp_TileMode));
+                pts, shaderColors, nullptr, 2, SkShader::kClamp_TileMode));
         SkRect r = SkRect::MakeXYWH(0, i * kRowHeight, width, kRowHeight);
         SkPaint p;
         p.setShader(shader);
@@ -70,6 +70,6 @@ DEF_SIMPLE_GM(transparency_check, canvas, 1792, 1080) {
         SkAutoTUnref<SkSurface> surface(SkSurface::NewRasterN32Premul(256, 9));
         make_transparency(surface->getCanvas(), 256.0f, 9.0f);
         canvas->scale(7.0f, 120.0f);
-        surface->draw(canvas, 0, 0, NULL);
+        surface->draw(canvas, 0, 0, nullptr);
     }
 }
diff --git a/gm/typeface.cpp b/gm/typeface.cpp
index b8f54abe37..d88efa51bf 100644
--- a/gm/typeface.cpp
+++ b/gm/typeface.cpp
@@ -135,7 +135,7 @@ protected:
         const size_t textLen = strlen(text);
 
         SkScalar x = SkIntToScalar(10);
-        SkScalar dy = paint.getFontMetrics(NULL);
+        SkScalar dy = paint.getFontMetrics(nullptr);
         SkScalar y = dy;
 
         if (fApplyKerning) {
diff --git a/gm/vertices.cpp b/gm/vertices.cpp
index 9533d81bb4..40dd9496ef 100644
--- a/gm/vertices.cpp
+++ b/gm/vertices.cpp
@@ -17,7 +17,7 @@ static SkShader* make_shader(SkScalar w, SkScalar h) {
     };
     const SkPoint pts[] = { { w/4, 0 }, { 3*w/4, h } };
 
-    return SkGradientShader::CreateLinear(pts, colors, NULL,
+    return SkGradientShader::CreateLinear(pts, colors, nullptr,
                                           SK_ARRAY_COUNT(colors),
                                           SkShader::kMirror_TileMode);
 }
@@ -30,7 +30,7 @@ class VerticesGM : public skiagm::GM {
     unsigned    fAlpha;
 
 public:
-    VerticesGM(unsigned alpha) : fShader(NULL), fAlpha(alpha) {
+    VerticesGM(unsigned alpha) : fShader(nullptr), fAlpha(alpha) {
     }
 
     virtual ~VerticesGM() {
@@ -85,8 +85,8 @@ protected:
             const SkColor*  fColors;
             const SkPoint*  fTexs;
         } rec[] = {
-            { fColors,  NULL },
-            { NULL,     fTexs },
+            { fColors,  nullptr },
+            { nullptr,     fTexs },
             { fColors,  fTexs },
         };
 
diff --git a/gm/verttext.cpp b/gm/verttext.cpp
index 9039685206..37cf37cbad 100644
--- a/gm/verttext.cpp
+++ b/gm/verttext.cpp
@@ -70,7 +70,7 @@ protected:
 
         p.setColor(0xFF0000FF);
         SkScalar adv[gLen];
-        int numChars = paint.getTextWidths(gText, gLen, adv, NULL);
+        int numChars = paint.getTextWidths(gText, gLen, adv, nullptr);
         for (int i = 0; i < numChars; ++i) {
             canvas->drawCircle(x, y, SK_Scalar1 * 3 / 2, p);
             if (paint.isVerticalText()) {
diff --git a/gm/verttext2.cpp b/gm/verttext2.cpp
index 3a3955ee7c..4896cc992a 100644
--- a/gm/verttext2.cpp
+++ b/gm/verttext2.cpp
@@ -19,8 +19,8 @@ namespace skiagm {
 class VertText2GM : public GM {
 public:
     VertText2GM()
-        : fProp(NULL)
-        , fMono(NULL) {
+        : fProp(nullptr)
+        , fMono(nullptr) {
     }
 
     virtual ~VertText2GM() {
diff --git a/gm/verylargebitmap.cpp b/gm/verylargebitmap.cpp
index 5e2dbd4f41..9b5496bc0f 100644
--- a/gm/verylargebitmap.cpp
+++ b/gm/verylargebitmap.cpp
@@ -15,7 +15,7 @@ static void make_bm(SkBitmap* bm, int width, int height, SkColor colors[2]) {
     SkCanvas canvas(*bm);
     SkPoint center = {SkIntToScalar(width)/2, SkIntToScalar(height)/2};
     SkScalar radius = 40;
-    SkShader* shader = SkGradientShader::CreateRadial(center, radius, colors, NULL, 2,
+    SkShader* shader = SkGradientShader::CreateRadial(center, radius, colors, nullptr, 2,
                                                       SkShader::kMirror_TileMode);
     SkPaint paint;
     paint.setShader(shader)->unref();
@@ -39,13 +39,13 @@ static void show_bm(SkCanvas* canvas, int width, int height, SkColor colors[2])
 
     canvas->save();
     canvas->clipRect(r);
-    canvas->drawBitmap(bm, 0, 0, NULL);
+    canvas->drawBitmap(bm, 0, 0, nullptr);
     canvas->restore();
     canvas->drawRect(r, paint);
 
     r.offset(SkIntToScalar(150), 0);
     // exercises extract bitmap, but not shader
-    canvas->drawBitmapRect(bm, ir, r, NULL);
+    canvas->drawBitmapRect(bm, ir, r, nullptr);
     canvas->drawRect(r, paint);
 
     r.offset(SkIntToScalar(150), 0);
diff --git a/gm/xfermodeimagefilter.cpp b/gm/xfermodeimagefilter.cpp
index 3efbbfad6a..80994a6ed8 100644
--- a/gm/xfermodeimagefilter.cpp
+++ b/gm/xfermodeimagefilter.cpp
@@ -138,8 +138,8 @@ protected:
             x = 0;
             y += fBitmap.height() + MARGIN;
         }
-        // Test NULL mode
-        filter.reset(SkXfermodeImageFilter::Create(NULL, background));
+        // Test nullptr mode
+        filter.reset(SkXfermodeImageFilter::Create(nullptr, background));
         paint.setImageFilter(filter);
         drawClippedBitmap(canvas, fBitmap, paint, x, y);
         x += fBitmap.width() + MARGIN;
diff --git a/gm/xfermodes.cpp b/gm/xfermodes.cpp
index aae8cbd234..bc1bc7ff73 100644
--- a/gm/xfermodes.cpp
+++ b/gm/xfermodes.cpp
@@ -255,14 +255,14 @@ protected:
                 p.setShader(s);
                 canvas->drawRect(r, p);
 
-                canvas->saveLayer(&r, NULL);
+                canvas->saveLayer(&r, nullptr);
                 draw_mode(canvas, mode, static_cast<SrcType>(sourceType),
                           r.fLeft, r.fTop);
                 canvas->restore();
 
                 r.inset(-SK_ScalarHalf, -SK_ScalarHalf);
                 p.setStyle(SkPaint::kStroke_Style);
-                p.setShader(NULL);
+                p.setShader(nullptr);
                 canvas->drawRect(r, p);
 
 #if 1
diff --git a/gm/xfermodes2.cpp b/gm/xfermodes2.cpp
index 192a279bf4..db48c03d20 100644
--- a/gm/xfermodes2.cpp
+++ b/gm/xfermodes2.cpp
@@ -55,7 +55,7 @@ protected:
             SkRect r = SkRect::MakeWH(w, h);
             canvas->drawRect(r, p);
 
-            canvas->saveLayer(&r, NULL);
+            canvas->saveLayer(&r, nullptr);
 
             p.setShader(fDst);
             canvas->drawRect(r, p);
@@ -67,8 +67,8 @@ protected:
 
             r.inset(-SK_ScalarHalf, -SK_ScalarHalf);
             p.setStyle(SkPaint::kStroke_Style);
-            p.setShader(NULL);
-            p.setXfermode(NULL);
+            p.setShader(nullptr);
+            p.setXfermode(nullptr);
             canvas->drawRect(r, p);
 
             canvas->restore();
diff --git a/gm/xfermodes3.cpp b/gm/xfermodes3.cpp
index c5e1695399..4466b1ce04 100644
--- a/gm/xfermodes3.cpp
+++ b/gm/xfermodes3.cpp
@@ -122,14 +122,14 @@ private:
      * dimensions exactly matching the layer size.
      */
     SkCanvas* possiblyCreateTempCanvas(SkCanvas* baseCanvas, int w, int h) {
-        SkCanvas* tempCanvas = NULL;
+        SkCanvas* tempCanvas = nullptr;
 #if SK_SUPPORT_GPU
         GrContext* context = baseCanvas->getGrContext();
         SkImageInfo baseInfo = baseCanvas->imageInfo();
         SkImageInfo info = SkImageInfo::Make(w, h, baseInfo.colorType(), baseInfo.alphaType(),
                                              baseInfo.profileType());
         SkAutoTUnref<SkSurface> surface(SkSurface::NewRenderTarget(context, SkSurface::kNo_Budgeted,
-                                        info, 0, NULL));
+                                        info, 0, nullptr));
         if (surface) {
             tempCanvas = SkRef(surface->getCanvas());
         }
@@ -147,8 +147,8 @@ private:
         SkRect r = SkRect::MakeWH(SkIntToScalar(w), SkIntToScalar(h));
 
         SkCanvas* modeCanvas;
-        if (NULL == layerCanvas) {
-            canvas->saveLayer(&r, NULL);
+        if (nullptr == layerCanvas) {
+            canvas->saveLayer(&r, nullptr);
             modeCanvas = canvas;
         } else {
             modeCanvas = layerCanvas;
@@ -159,9 +159,9 @@ private:
         bgPaint.setShader(fBGShader);
         modeCanvas->drawRect(r, bgPaint);
         modeCanvas->drawRect(r, modePaint);
-        modeCanvas = NULL;
+        modeCanvas = nullptr;
 
-        if (NULL == layerCanvas) {
+        if (nullptr == layerCanvas) {
             canvas->restore();
         } else {
             SkAutoROCanvasPixels ropixels(layerCanvas);
@@ -205,7 +205,7 @@ private:
         bmpPaint.setShader(SkGradientShader::CreateRadial(kCenter,
                                                           3 * SkIntToScalar(kSize) / 4,
                                                           kColors,
-                                                          NULL,
+                                                          nullptr,
                                                           SK_ARRAY_COUNT(kColors),
                                                           SkShader::kRepeat_TileMode))->unref();
 
diff --git a/gm/yuvtorgbeffect.cpp b/gm/yuvtorgbeffect.cpp
index 9d5ec450f9..4fd23efaa7 100644
--- a/gm/yuvtorgbeffect.cpp
+++ b/gm/yuvtorgbeffect.cpp
@@ -68,26 +68,26 @@ protected:
 
     void onDraw(SkCanvas* canvas) override {
         GrRenderTarget* rt = canvas->internal_private_accessTopLayerRenderTarget();
-        if (NULL == rt) {
+        if (nullptr == rt) {
             return;
         }
         GrContext* context = rt->getContext();
-        if (NULL == context) {
+        if (nullptr == context) {
             this->drawGpuOnlyMessage(canvas);
             return;
         }
 
         GrTestTarget tt;
         context->getTestTarget(&tt);
-        if (NULL == tt.target()) {
+        if (nullptr == tt.target()) {
             SkDEBUGFAIL("Couldn't get Gr test target.");
             return;
         }
 
         SkAutoTUnref<GrTexture> texture[3];
-        texture[0].reset(GrRefCachedBitmapTexture(context, fBmp[0], NULL));
-        texture[1].reset(GrRefCachedBitmapTexture(context, fBmp[1], NULL));
-        texture[2].reset(GrRefCachedBitmapTexture(context, fBmp[2], NULL));
+        texture[0].reset(GrRefCachedBitmapTexture(context, fBmp[0], nullptr));
+        texture[1].reset(GrRefCachedBitmapTexture(context, fBmp[1], nullptr));
+        texture[2].reset(GrRefCachedBitmapTexture(context, fBmp[2], nullptr));
 
         if (!texture[0] || !texture[1] || !texture[2]) {
             return;