Clear m_lastImageId for software compositor

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 12 matching lines @@
  */
 
 #include "config.h"
 
 #include "platform/graphics/Canvas2DLayerBridge.h"
 
 #include "SkDeferredCanvas.h"
 #include "SkSurface.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "public/platform/Platform.h"
+#include "public/platform/WebExternalBitmap.h"
 #include "public/platform/WebGraphicsContext3DProvider.h"
 #include "public/platform/WebThread.h"
 #include "third_party/skia/include/core/SkDevice.h"
 #include "web/tests/MockWebGraphicsContext3D.h"
 #include "wtf/RefPtr.h"
 
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 using namespace WebCore;
@@ skipping 40 matching lines @@
         m_layerBridge->beginDestruction();
     }
 
     Canvas2DLayerBridge* operator->() { return m_layerBridge.get(); }
     Canvas2DLayerBridge* get() { return m_layerBridge.get(); }
 
 private:
     RefPtr<Canvas2DLayerBridge> m_layerBridge;
 };
 
+class NullWebExternalBitmap : public WebExternalBitmap {
+public:
+    virtual WebSize size()
+    {
+        return WebSize();
+    }
+
+    virtual void setSize(WebSize)
+    {
+    }
+
+    virtual uint8* pixels()
+    {
+        return 0;
+    }
+};
+
 } // namespace
 
 class Canvas2DLayerBridgeTest : public Test {
 protected:
     void fullLifecycleTest()
     {
         MockCanvasContext mainMock;
         OwnPtr<MockWebGraphicsContext3DProvider> mainMockProvider = adoptPtr(new MockWebGraphicsContext3DProvider(&mainMock));
         OwnPtr<SkDeferredCanvas> canvas = adoptPtr(SkDeferredCanvas::Create(SkSurface::NewRasterPMColor(300, 150)));
 
         ::testing::Mock::VerifyAndClearExpectations(&mainMock);
 
         {
             Canvas2DLayerBridgePtr bridge(adoptRef(new Canvas2DLayerBridge(mainMockProvider.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);
     }
+
+    void prepareMailboxWithBitmapTest()
+    {
+        MockCanvasContext mainMock;
+        OwnPtr<SkDeferredCanvas> canvas = adoptPtr(SkDeferredCanvas::Create(SkSurface::NewRasterPMColor(300, 150)));
+        OwnPtr<MockWebGraphicsContext3DProvider> mainMockProvider = adoptPtr(new MockWebGraphicsContext3DProvider(&mainMock));
+        Canvas2DLayerBridgePtr bridge(adoptRef(new Canvas2DLayerBridge(mainMockProvider.release(), canvas.release(), 0, NonOpaque)));
+        bridge->m_lastImageId = 1;
+
+        NullWebExternalBitmap bitmap;
+        bridge->prepareMailbox(0, &bitmap);
+        EXPECT_EQ(0u, bridge->m_lastImageId);
+    }
 };
 
 namespace {
 
 TEST_F(Canvas2DLayerBridgeTest, testFullLifecycleSingleThreaded)
 {
     fullLifecycleTest();
 }
 
+TEST_F(Canvas2DLayerBridgeTest, prepareMailboxWithBitmapTest)
+{
+    prepareMailboxWithBitmapTest();
+}
+
 } // namespace