Revert of add compose-colorfilter (patchset #2 id:20001 of https://codereview.chromium.org/969673002/)

Reason for revert:
need to register subclass for serialization

Original issue's description:
> add compose-colorfilter
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/b675a73c1f3f4a433c4893199a0bd11126dfe130

TBR=fmalita@chromium.org,bsalomon@google.com,reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/971653002

3 files changed, 23 insertions, 164 deletions

diff --git a/gm/tablecolorfilter.cpp b/gm/tablecolorfilter.cpp
index 2acb15c677..a49859bf8f 100644
--- a/gm/tablecolorfilter.cpp
+++ b/gm/tablecolorfilter.cpp
@@ -11,15 +11,6 @@
 #include "SkGradientShader.h"
 #include "SkTableColorFilter.h"
 
-static SkShader* make_shader0(int w, int h) {
-    SkPoint pts[] = { {0, 0}, {SkIntToScalar(w), SkIntToScalar(h)} };
-    SkColor colors[] = {
-        SK_ColorBLACK, SK_ColorGREEN, SK_ColorCYAN,
-        SK_ColorRED, 0, SK_ColorBLUE, SK_ColorWHITE
-    };
-    return SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
-                                          SkShader::kClamp_TileMode);
-}
 static void make_bm0(SkBitmap* bm) {
     int W = 120;
     int H = 120;
@@ -28,29 +19,34 @@ static void make_bm0(SkBitmap* bm) {
 
     SkCanvas canvas(*bm);
     SkPaint paint;
-    paint.setShader(make_shader0(W, H))->unref();
-    canvas.drawPaint(paint);
-}
-static SkShader* make_shader1(int w, int h) {
-    SkScalar cx = SkIntToScalar(w)/2;
-    SkScalar cy = SkIntToScalar(h)/2;
+    SkPoint pts[] = { {0, 0}, {SkIntToScalar(W), SkIntToScalar(H)} };
     SkColor colors[] = {
-        SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE,
+        SK_ColorBLACK, SK_ColorGREEN, SK_ColorCYAN,
+        SK_ColorRED, 0, SK_ColorBLUE, SK_ColorWHITE
     };
-    return SkGradientShader::CreateRadial(SkPoint::Make(cx, cy), cx, colors, NULL,
-                                          SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode);
+    SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
+                                                 SkShader::kClamp_TileMode);
+    paint.setShader(s)->unref();
+    canvas.drawPaint(paint);
 }
 static void make_bm1(SkBitmap* bm) {
     int W = 120;
     int H = 120;
-    SkScalar cx = SkIntToScalar(W)/2;
-    SkScalar cy = SkIntToScalar(H)/2;
     bm->allocN32Pixels(W, H);
     bm->eraseColor(SK_ColorTRANSPARENT);
 
     SkCanvas canvas(*bm);
     SkPaint paint;
-    paint.setShader(make_shader1(W, H))->unref();
+    SkScalar cx = SkIntToScalar(W)/2;
+    SkScalar cy = SkIntToScalar(H)/2;
+    SkColor colors[] = {
+        SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE,
+    };
+    SkShader* s = SkGradientShader::CreateRadial(SkPoint::Make(SkIntToScalar(W)/2,
+                                                               SkIntToScalar(H)/2),
+                                                 SkIntToScalar(W)/2, colors, NULL, SK_ARRAY_COUNT(colors),
+                                                 SkShader::kClamp_TileMode);
+    paint.setShader(s)->unref();
     paint.setAntiAlias(true);
     canvas.drawCircle(cx, cy, cx, paint);
 }
@@ -188,69 +184,8 @@ protected:
 private:
     typedef GM INHERITED;
 };
-DEF_GM( return new TableColorFilterGM; )
 
 //////////////////////////////////////////////////////////////////////////////
 
-class ComposeColorFilterGM : public skiagm::GM {
-public:
-    ComposeColorFilterGM() {}
-    
-protected:
-    virtual SkString onShortName() {
-        return SkString("composecolorfilter");
-    }
-    
-    virtual SkISize onISize() {
-        return SkISize::Make(730, 730);
-    }
-
-    virtual void onDraw(SkCanvas* canvas) {
-        SkBitmap bm;
-        make_bm1(&bm);
-
-        canvas->drawColor(0xFFDDDDDD);
-
-        SkColor colors[] = { SK_ColorCYAN, SK_ColorMAGENTA, SK_ColorYELLOW };
-        SkXfermode::Mode modes[] = {
-            SkXfermode::kOverlay_Mode,
-            SkXfermode::kDarken_Mode,
-            SkXfermode::kColorBurn_Mode,
-            SkXfermode::kExclusion_Mode,
-        };
-
-        const int MODES = SK_ARRAY_COUNT(modes) * SK_ARRAY_COUNT(colors);
-        SkAutoTUnref<SkColorFilter> filters[MODES];
-        int index = 0;
-        for (size_t i = 0; i < SK_ARRAY_COUNT(modes); ++i) {
-            for (size_t j = 0; j < SK_ARRAY_COUNT(colors); ++j) {
-                filters[index++].reset(SkColorFilter::CreateModeFilter(colors[j], modes[i]));
-            }
-        }
-
-        SkPaint paint;
-        paint.setShader(make_shader1(50, 50))->unref();
-        SkRect r = SkRect::MakeWH(50, 50);
-        const SkScalar spacer = 10;
-
-        canvas->translate(spacer, spacer);
-
-        for (size_t y = 0; y < MODES; ++y) {
-            canvas->save();
-            for (size_t x = 0; x < MODES; ++x) {
-                SkAutoTUnref<SkColorFilter> compose(SkColorFilter::CreateComposeFilter(filters[y],
-                                                                                       filters[x]));
-                paint.setColorFilter(compose);
-                canvas->drawRect(r, paint);
-                canvas->translate(r.width() + spacer, 0);
-            }
-            canvas->restore();
-            canvas->translate(0, r.height() + spacer);
-        }
-    }
-    
-private:
-    typedef GM INHERITED;
-};
-DEF_GM( return new ComposeColorFilterGM; )
-
+static skiagm::GM* MyFactory(void*) { return new TableColorFilterGM; }
+static skiagm::GMRegistry reg(MyFactory);
diff --git a/include/core/SkColorFilter.h b/include/core/SkColorFilter.h
index bb628053a6..929607a398 100644
--- a/include/core/SkColorFilter.h
+++ b/include/core/SkColorFilter.h
@@ -123,12 +123,6 @@ public:
     */
     static SkColorFilter* CreateLightingFilter(SkColor mul, SkColor add);
 
-    /** Construct a colorfilter whose effect is to first apply the inner filter and then apply
-     *  the outer filter to the result of the inner's.
-     *  The reference counts for outer and inner are incremented.
-     */
-    static SkColorFilter* CreateComposeFilter(SkColorFilter* outer, SkColorFilter* inner);
-
     /** A subclass may implement this factory function to work with the GPU backend. If the return
         is non-NULL then the caller owns a ref on the returned object.
      */
diff --git a/src/core/SkColorFilter.cpp b/src/core/SkColorFilter.cpp
index 8c760be6cf..aadb29cb2d 100644
--- a/src/core/SkColorFilter.cpp
+++ b/src/core/SkColorFilter.cpp
@@ -6,9 +6,12 @@
  */
 
 #include "SkColorFilter.h"
+
 #include "SkReadBuffer.h"
-#include "SkString.h"
 #include "SkWriteBuffer.h"
+#include "SkShader.h"
+#include "SkUnPreMultiply.h"
+#include "SkString.h"
 
 bool SkColorFilter::asColorMode(SkColor* color, SkXfermode::Mode* mode) const {
     return false;
@@ -40,76 +43,3 @@ SkColor SkColorFilter::filterColor(SkColor c) const {
 GrFragmentProcessor* SkColorFilter::asFragmentProcessor(GrContext*) const {
     return NULL;
 }
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-class SkComposeColorFilter : public SkColorFilter {
-public:
-    SkComposeColorFilter(SkColorFilter* outer, SkColorFilter* inner)
-        : fOuter(SkRef(outer))
-        , fInner(SkRef(inner))
-    {}
-    
-    uint32_t getFlags() const SK_OVERRIDE {
-        // Can only claim alphaunchanged and 16bit support if both our proxys do.
-        return fOuter->getFlags() & fInner->getFlags();
-    }
-    
-    void filterSpan(const SkPMColor shader[], int count, SkPMColor result[]) const SK_OVERRIDE {
-        fInner->filterSpan(shader, count, result);
-        fOuter->filterSpan(result, count, result);
-    }
-    
-    void filterSpan16(const uint16_t shader[], int count, uint16_t result[]) const SK_OVERRIDE {
-        SkASSERT(this->getFlags() & kHasFilter16_Flag);
-        fInner->filterSpan16(shader, count, result);
-        fOuter->filterSpan16(result, count, result);
-    }
-    
-#ifndef SK_IGNORE_TO_STRING
-    void toString(SkString* str) const SK_OVERRIDE {
-        SkString outerS, innerS;
-        fOuter->toString(&outerS);
-        fInner->toString(&innerS);
-        str->appendf("SkComposeColorFilter: outer(%s) inner(%s)", outerS.c_str(), innerS.c_str());
-    }
-#endif
-
-#if 0   // TODO: should we support composing the fragments?
-#if SK_SUPPORT_GPU
-    GrFragmentProcessor* asFragmentProcessor(GrContext*) const SK_OVERRIDE;
-#endif
-#endif
-
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposeColorFilter)
-    
-protected:
-    void flatten(SkWriteBuffer& buffer) const SK_OVERRIDE {
-        buffer.writeFlattenable(fOuter);
-        buffer.writeFlattenable(fInner);
-    }
-    
-private:
-    SkAutoTUnref<SkColorFilter> fOuter;
-    SkAutoTUnref<SkColorFilter> fInner;
-    
-    typedef SkColorFilter INHERITED;
-};
-
-SkFlattenable* SkComposeColorFilter::CreateProc(SkReadBuffer& buffer) {
-    SkAutoTUnref<SkColorFilter> outer(buffer.readColorFilter());
-    SkAutoTUnref<SkColorFilter> inner(buffer.readColorFilter());
-    return CreateComposeFilter(outer, inner);
-}
-
-SkColorFilter* SkColorFilter::CreateComposeFilter(SkColorFilter* outer, SkColorFilter* inner) {
-    if (!outer) {
-        return SkSafeRef(inner);
-    }
-    if (!inner) {
-        return SkSafeRef(outer);
-    }
-    return SkNEW_ARGS(SkComposeColorFilter, (outer, inner));
-}
-
-