Use recomputed interest rect only if it changed enough

third_party/WebKit/Source/platform/graphics/ImageLayerChromiumTest.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 19 matching lines @@
 #include "third_party/skia/include/core/SkSurface.h"
 #include "wtf/PassOwnPtr.h"
 #include <gtest/gtest.h>
 
 namespace blink {
 
 namespace {
 
 class MockGraphicsLayerClient : public GraphicsLayerClient {
 public:
-    void paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect*) const override { }
-
-    String debugName(const GraphicsLayer*) override { return String(); }
+    IntRect computeInterestRect(const GraphicsLayer*, const IntRect&) const { return IntRect(); }
+    void paintContents(const GraphicsLayer*, GraphicsContext&, GraphicsLayerPaintingPhase, const IntRect&) const override { }
+    String debugName(const GraphicsLayer*) const override { return String(); }
 };
 
 class TestImage : public Image {
 public:
     static PassRefPtr<TestImage> create(const IntSize& size, bool opaque)
     {
         return adoptRef(new TestImage(size, opaque));
     }
 
     bool currentFrameKnownToBeOpaque() override
@@ skipping 90 matching lines @@
     ASSERT_FALSE(graphicsLayer->contentsLayer());
 
     graphicsLayer->setContentsToImage(opaqueImage.get());
     ASSERT_TRUE(graphicsLayer->contentsLayer()->opaque());
 
     graphicsLayer->setContentsToImage(nonOpaqueImage.get());
     ASSERT_FALSE(graphicsLayer->contentsLayer()->opaque());
 }
 
 } // namespace blink