Base SkAutoTUnref on skstd::unique_ptr.

To further consolidate the various unique owning classes, this bases
SkAutoTUnref on skstd::unique_ptr. Users are updated because of two
breaking changes, swap now takes a reference and reset no longer
returns its argument.

Review URL: https://codereview.chromium.org/1370803002

6 files changed, 22 insertions, 46 deletions

diff --git a/include/core/SkRefCnt.h b/include/core/SkRefCnt.h
index 1ba59b33c0..0e8d857722 100644
--- a/include/core/SkRefCnt.h
+++ b/include/core/SkRefCnt.h
@@ -9,6 +9,7 @@
 #define SkRefCnt_DEFINED
 
 #include "../private/SkAtomics.h"
+#include "../private/SkUniquePtr.h"
 #include "SkTypes.h"
 
 /** \class SkRefCntBase
@@ -143,7 +144,7 @@ class SK_API SkRefCnt : public SkRefCntBase { };
     } while (0)
 
 
-/** Call obj->ref() and return obj. The obj must not be NULL.
+/** Call obj->ref() and return obj. The obj must not be nullptr.
  */
 template <typename T> static inline T* SkRef(T* obj) {
     SkASSERT(obj);
@@ -171,51 +172,25 @@ template <typename T> static inline void SkSafeUnref(T* obj) {
 template<typename T> static inline void SkSafeSetNull(T*& obj) {
     if (obj) {
         obj->unref();
-        obj = NULL;
+        obj = nullptr;
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
+template <typename T> struct SkTUnref {
+    void operator()(T* t) { t->unref(); }
+};
+
 /**
  *  Utility class that simply unref's its argument in the destructor.
  */
-template <typename T> class SkAutoTUnref : SkNoncopyable {
+template <typename T> class SkAutoTUnref : public skstd::unique_ptr<T, SkTUnref<T>> {
 public:
-    explicit SkAutoTUnref(T* obj = NULL) : fObj(obj) {}
-    ~SkAutoTUnref() { SkSafeUnref(fObj); }
-
-    T* get() const { return fObj; }
-
-    T* reset(T* obj) {
-        SkSafeUnref(fObj);
-        fObj = obj;
-        return obj;
-    }
-
-    void swap(SkAutoTUnref* other) {
-        T* tmp = fObj;
-        fObj = other->fObj;
-        other->fObj = tmp;
-    }
+    explicit SkAutoTUnref(T* obj = nullptr) : skstd::unique_ptr<T, SkTUnref<T>>(obj) {}
 
-    /**
-     *  Return the hosted object (which may be null), transferring ownership.
-     *  The reference count is not modified, and the internal ptr is set to NULL
-     *  so unref() will not be called in our destructor. A subsequent call to
-     *  detach() will do nothing and return null.
-     */
-    T* detach() {
-        T* obj = fObj;
-        fObj = NULL;
-        return obj;
-    }
-
-    T* operator->() const { return fObj; }
-    operator T*() const { return fObj; }
-
-private:
-    T*  fObj;
+    T* detach() { return this->release(); }
+    operator T*() const { return this->get(); }
 };
 // Can't use the #define trick below to guard a bare SkAutoTUnref(...) because it's templated. :(
 
diff --git a/src/core/SkPath.cpp b/src/core/SkPath.cpp
index 97e34386dc..1326362524 100644
--- a/src/core/SkPath.cpp
+++ b/src/core/SkPath.cpp
@@ -180,7 +180,7 @@ bool operator==(const SkPath& a, const SkPath& b) {
 
 void SkPath::swap(SkPath& that) {
     if (this != &that) {
-        fPathRef.swap(&that.fPathRef);
+        fPathRef.swap(that.fPathRef);
         SkTSwap<int>(fLastMoveToIndex, that.fLastMoveToIndex);
         SkTSwap<uint8_t>(fFillType, that.fFillType);
         SkTSwap<uint8_t>(fConvexity, that.fConvexity);
diff --git a/src/effects/SkGpuBlurUtils.cpp b/src/effects/SkGpuBlurUtils.cpp
index fd27cc3600..5690c2893f 100644
--- a/src/effects/SkGpuBlurUtils.cpp
+++ b/src/effects/SkGpuBlurUtils.cpp
@@ -231,7 +231,7 @@ GrTexture* GaussianBlur(GrContext* context,
         dstDrawContext->drawNonAARectToRect(dstTexture->asRenderTarget(), clip, paint,
                                             SkMatrix::I(), dstRect, srcRect);
 
-        srcDrawContext.swap(&dstDrawContext);
+        srcDrawContext.swap(dstDrawContext);
         srcRect = dstRect;
         srcTexture = dstTexture;
         SkTSwap(dstTexture, tempTexture);
@@ -254,7 +254,7 @@ GrTexture* GaussianBlur(GrContext* context,
         convolve_gaussian_2d(dstDrawContext, dstTexture->asRenderTarget(), clip, srcRect, dstRect,
                              srcTexture, radiusX, radiusY, sigmaX, sigmaY, cropToRect, srcIRect);
 
-        srcDrawContext.swap(&dstDrawContext);
+        srcDrawContext.swap(dstDrawContext);
         srcRect = dstRect;
         srcTexture = dstTexture;
         SkTSwap(dstTexture, tempTexture);
@@ -286,7 +286,7 @@ GrTexture* GaussianBlur(GrContext* context,
                               srcTexture, Gr1DKernelEffect::kX_Direction, radiusX, sigmaX,
                               cropToRect);
 
-            srcDrawContext.swap(&dstDrawContext);
+            srcDrawContext.swap(dstDrawContext);
             srcTexture = dstTexture;
             srcRect = dstRect;
             SkTSwap(dstTexture, tempTexture);
@@ -319,7 +319,7 @@ GrTexture* GaussianBlur(GrContext* context,
                               dstRect, srcTexture, Gr1DKernelEffect::kY_Direction, radiusY, sigmaY,
                               cropToRect);
 
-            srcDrawContext.swap(&dstDrawContext);
+            srcDrawContext.swap(dstDrawContext);
             srcTexture = dstTexture;
             srcRect = dstRect;
             SkTSwap(dstTexture, tempTexture);
@@ -355,7 +355,7 @@ GrTexture* GaussianBlur(GrContext* context,
         dstDrawContext->drawNonAARectToRect(dstTexture->asRenderTarget(), clip, paint,
                                             SkMatrix::I(), dstRect, srcRect);
 
-        srcDrawContext.swap(&dstDrawContext);
+        srcDrawContext.swap(dstDrawContext);
         srcRect = dstRect;
         srcTexture = dstTexture;
         SkTSwap(dstTexture, tempTexture);
diff --git a/tests/FontHostStreamTest.cpp b/tests/FontHostStreamTest.cpp
index 7843a412a1..f4cc5bf3a9 100644
--- a/tests/FontHostStreamTest.cpp
+++ b/tests/FontHostStreamTest.cpp
@@ -92,7 +92,8 @@ DEF_TEST(FontHostStream, reporter) {
         SkTypeface* origTypeface = paint.getTypeface();
         SkAutoTUnref<SkTypeface> aur;
         if (nullptr == origTypeface) {
-            origTypeface = aur.reset(SkTypeface::RefDefault());
+            aur.reset(SkTypeface::RefDefault());
+            origTypeface = aur.get();
         }
 
         int ttcIndex;
diff --git a/tools/CopyTilesRenderer.cpp b/tools/CopyTilesRenderer.cpp
index f5ffb25d03..a78d772c68 100644
--- a/tools/CopyTilesRenderer.cpp
+++ b/tools/CopyTilesRenderer.cpp
@@ -35,7 +35,7 @@ namespace sk_tools {
         SkASSERT(pict != nullptr);
         // Only work with absolute widths (as opposed to percentages).
         SkASSERT(this->getTileWidth() != 0 && this->getTileHeight() != 0);
-        fPicture.reset(pict)->ref();
+        fPicture.reset(SkRef(pict));
         this->CopyString(&fWritePath, writePath);
         this->CopyString(&fMismatchPath, mismatchPath);
         this->CopyString(&fInputFilename, inputFilename);
diff --git a/tools/PictureRenderer.cpp b/tools/PictureRenderer.cpp
index 21bb933b35..19ee7b5f2a 100644
--- a/tools/PictureRenderer.cpp
+++ b/tools/PictureRenderer.cpp
@@ -76,7 +76,7 @@ void PictureRenderer::init(const SkPicture* pict,
         return;
     }
 
-    fPicture.reset(pict)->ref();
+    fPicture.reset(SkRef(pict));
     fCanvas.reset(this->setupCanvas());
 }
 
@@ -503,7 +503,7 @@ void TiledPictureRenderer::init(const SkPicture* pict, const SkString* writePath
 
     // Do not call INHERITED::init(), which would create a (potentially large) canvas which is not
     // used by bench_pictures.
-    fPicture.reset(pict)->ref();
+    fPicture.reset(SkRef(pict));
     this->CopyString(&fWritePath, writePath);
     this->CopyString(&fMismatchPath, mismatchPath);
     this->CopyString(&fInputFilename, inputFilename);