Free temporary GPU and memory resources held by inactive or hidden 2D canvases

Source/web/tests/Canvas2DLayerBridgeTest.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 52 matching lines @@
         m_layerBridge->beginDestruction();
     }
 
     Canvas2DLayerBridge* operator->() { return m_layerBridge.get(); }
     Canvas2DLayerBridge* get() { return m_layerBridge.get(); }
 
 private:
     RefPtr<Canvas2DLayerBridge> m_layerBridge;
 };
 
+class FakeCanvas2DLayerBridgeClient : public Canvas2DLayerBridgeClient {
+public:
+    virtual ~FakeCanvas2DLayerBridgeClient() { }
+    virtual bool hidden() const OVERRIDE { return false; }
+};
+
 } // namespace
 
 class Canvas2DLayerBridgeTest : public Test {
 protected:
     void fullLifecycleTest()
     {
         RefPtr<GraphicsContext3D> mainContext = GraphicsContext3D::createGraphicsContextFromWebContext(adoptPtr(new MockCanvasContext));
 
         MockCanvasContext& mainMock = *static_cast<MockCanvasContext*>(mainContext->webContext());
 
         OwnPtr<SkDeferredCanvas> canvas = adoptPtr(SkDeferredCanvas::Create(SkSurface::NewRasterPMColor(300, 150)));
 
         ::testing::Mock::VerifyAndClearExpectations(&mainMock);
 
         {
-            Canvas2DLayerBridgePtr bridge(adoptRef(new Canvas2DLayerBridge(mainContext.release(), canvas.release(), 0, NonOpaque)));
+            FakeCanvas2DLayerBridgeClient client;
+            Canvas2DLayerBridgePtr bridge(adoptRef(new Canvas2DLayerBridge(&client, mainContext.release(), canvas.release(), 0, NonOpaque)));
 
             ::testing::Mock::VerifyAndClearExpectations(&mainMock);
 
             EXPECT_CALL(mainMock, flush());
             unsigned textureId = bridge->getBackingTexture();
             EXPECT_EQ(textureId, 0u);
 
             ::testing::Mock::VerifyAndClearExpectations(&mainMock);
         } // bridge goes out of scope here
 
         ::testing::Mock::VerifyAndClearExpectations(&mainMock);
     }
 };
 
 namespace {
 
 TEST_F(Canvas2DLayerBridgeTest, testFullLifecycleSingleThreaded)
 {
     fullLifecycleTest();
 }
 
 } // namespace