Fixing Canvas2DLayerBridge to handle lost graphics contexts

Source/WebKit/chromium/tests/Canvas2DLayerManagerTest.cpp

 /*
  * Copyright (C) 2012 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 25 matching lines @@
 
 using namespace WebCore;
 using testing::InSequence;
 using testing::Return;
 using testing::Test;
 
 
 class FakeCanvas2DLayerBridge : public Canvas2DLayerBridge {
 public:
     FakeCanvas2DLayerBridge(PassRefPtr<GraphicsContext3D> context, SkDeferredCanvas* canvas)
-        : Canvas2DLayerBridge(context, canvas, NonOpaque, SingleThread)
+        : Canvas2DLayerBridge(context, canvas)
         , m_freeableBytes(0)
         , m_freeMemoryIfPossibleCount(0)
         , m_flushCount(0)
     {
+        init(NonOpaque, SingleThread);
     }
 
     virtual size_t storageAllocatedForRecording() OVERRIDE
     {
         // Because the fake layer has no canvas to query, just
         // return status quo. Allocation changes that would normally be
         // initiated by the canvas can be faked by invoking
         // storageAllocatedForRecordingChanged directly from the test code.
         return m_bytesAllocated;
     }
@@ skipping 13 matching lines @@
         m_bytesAllocated -= bytesFreed;
         return bytesFreed;
     }
 
     virtual void flush() OVERRIDE
     {
         flushedDrawCommands();
         m_flushCount++;
     }
 
+    virtual bool isValid() OVERRIDE
+    {
+        return true;
+    }
 public:
     size_t m_freeableBytes;
     int m_freeMemoryIfPossibleCount;
     int m_flushCount;
 };
 
 static PassOwnPtr<SkDeferredCanvas> createCanvas(GraphicsContext3D* context) {
     SkAutoTUnref<SkDevice> device(new SkDevice(SkBitmap::kARGB_8888_Config, 1, 1));
     return adoptPtr(new SkDeferredCanvas(device.get()));
 }
@@ skipping 162 matching lines @@
     flushEvictionTest();
 }
 
 TEST_F(Canvas2DLayerManagerTest, testDeferredFrame)
 {
     deferredFrameTest();
 }
 
 } // namespace