Initial implementation of display list backed 2D canvases

Source/platform/graphics/RecordingImageBufferSurface.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef RecordingImageBufferSurface_h
+#define RecordingImageBufferSurface_h
+
+#include "platform/graphics/ImageBufferSurface.h"
+#include "wtf/OwnPtr.h"
+#include "wtf/RefPtr.h"
+
+class SkPicture;
+class SkPictureRecorder;
+
+namespace WebCore {
+
+class GraphicsContext;
+
+class PLATFORM_EXPORT RecordingImageBufferSurface : public ImageBufferSurface {
+    WTF_MAKE_NONCOPYABLE(RecordingImageBufferSurface); WTF_MAKE_FAST_ALLOCATED;
+public:
+    RecordingImageBufferSurface(const IntSize&, OpacityMode = NonOpaque);
+    virtual ~RecordingImageBufferSurface();
+

[Sergey, 2014/07/21 04:57:10]

Could you please group and add a comment which of these methods are derived from
ImageBufferSurface, like it is done in
https://chromium.googlesource.com/chromium/blink/+/master/Source/platform/gra...
?

[Justin Novosad, 2014/07/21 17:26:46]

They all are, but yes good idea.

+    virtual SkCanvas* canvas() const OVERRIDE;
+    virtual PassRefPtr<SkPicture> getPicture() OVERRIDE;
+    virtual bool isValid() const OVERRIDE { return true; }
+    virtual void willReadback() OVERRIDE;
+    virtual void didClearCanvas() OVERRIDE;
+    virtual void setImageBuffer(ImageBuffer*) OVERRIDE;
+
+private:
+    void fallBackToRasterCanvas();
+    void initializeCurrentFrame();
+    bool handleOpaqueFrame();
+
+    OwnPtr<SkPictureRecorder> m_currentFrame;
+    RefPtr<SkPicture> m_previousFrame;
+    OwnPtr<SkCanvas> m_rasterCanvas;
+    GraphicsContext* m_graphicsContext;
+    bool m_frameWasCleared;
+};
+
+} // namespace WebCore
+
+#endif