Fixing Canvas2DLayerBridge to handle lost graphics contexts

Source/core/platform/graphics/chromium/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 36 matching lines @@
 
 class MockCanvasContext : public FakeWebGraphicsContext3D {
 public:
     MOCK_METHOD0(flush, void(void));
     MOCK_METHOD0(createTexture, unsigned(void));
     MOCK_METHOD1(deleteTexture, void(unsigned));
 
     virtual GrGLInterface* onCreateGrGLInterface() OVERRIDE { return 0; }
 };
 
+class FakeCanvas2DLayerBridge : public Canvas2DLayerBridge {
+public:
+    static PassOwnPtr<FakeCanvas2DLayerBridge> create(PassRefPtr<GraphicsContext3D> context, SkDeferredCanvas* canvas, OpacityMode opacityMode)
+    {
+        return adoptPtr(new FakeCanvas2DLayerBridge(context, canvas, opacityMode));
+    }
+protected:
+    FakeCanvas2DLayerBridge(PassRefPtr<GraphicsContext3D> context, SkDeferredCanvas* canvas, OpacityMode opacityMode) :
+        Canvas2DLayerBridge(context, canvas, opacityMode)
+    { }
+};
+
 } // namespace
 
 class Canvas2DLayerBridgeTest : public Test {
 protected:
     void fullLifecycleTest()
     {
         RefPtr<GraphicsContext3D> mainContext = GraphicsContext3D::createGraphicsContextFromWebContext(adoptPtr(new MockCanvasContext));
 
         MockCanvasContext& mainMock = *static_cast<MockCanvasContext*>(mainContext->webContext());
 
         SkDevice device(SkBitmap::kARGB_8888_Config, 300, 150);
         SkDeferredCanvas canvas(&device);
 
         ::testing::Mock::VerifyAndClearExpectations(&mainMock);
 
-        OwnPtr<Canvas2DLayerBridge> bridge = Canvas2DLayerBridge::create(mainContext.release(), &canvas, Canvas2DLayerBridge::NonOpaque);
+        OwnPtr<Canvas2DLayerBridge> bridge = FakeCanvas2DLayerBridge::create(mainContext.release(), &canvas, Canvas2DLayerBridge::NonOpaque);
 
         ::testing::Mock::VerifyAndClearExpectations(&mainMock);
 
         EXPECT_CALL(mainMock, flush());
         unsigned textureId = bridge->backBufferTexture();
         EXPECT_EQ(textureId, 0u);
 
         ::testing::Mock::VerifyAndClearExpectations(&mainMock);
 
         bridge.clear();
 
         ::testing::Mock::VerifyAndClearExpectations(&mainMock);
     }
 };
 
 namespace {
 
 TEST_F(Canvas2DLayerBridgeTest, testFullLifecycleSingleThreaded)
 {
     fullLifecycleTest();
 }
 
 } // namespace