Refactoring ImageBuffer to decouple it from Canvas2DLayerBridge

Source/platform/graphics/UnacceleratedImageBufferSurface.h

Index: Source/platform/graphics/UnacceleratedImageBufferSurface.h
diff --git a/Source/core/rendering/LayoutRectRecorder.h b/Source/platform/graphics/UnacceleratedImageBufferSurface.h
similarity index 72%
copy from Source/core/rendering/LayoutRectRecorder.h
copy to Source/platform/graphics/UnacceleratedImageBufferSurface.h
index 9fd331e2aca95cb262bbbd4e738d3b78286caa2d..3696a1094aebfe5b11780f33a015b977af5560c1 100644
--- a/Source/core/rendering/LayoutRectRecorder.h
+++ b/Source/platform/graphics/UnacceleratedImageBufferSurface.h
@@ -28,32 +28,27 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef LayoutRectRecorder_h
-#define LayoutRectRecorder_h
+#ifndef UnacceleratedImageBufferSurface_h
+#define UnacceleratedImageBufferSurface_h
 
-#include "platform/geometry/LayoutRect.h"
-#include "wtf/Noncopyable.h"
+#include "platform/graphics/ImageBufferSurface.h"
+#include "wtf/OwnPtr.h"
 
 namespace WebCore {
 
-class RenderLayerModelObject;
-class RenderObject;
-
-class LayoutRectRecorder {
-    WTF_MAKE_NONCOPYABLE(LayoutRectRecorder);
+class UnacceleratedImageBufferSurface : public ImageBufferSurface {
+    WTF_MAKE_NONCOPYABLE(UnacceleratedImageBufferSurface); WTF_MAKE_FAST_ALLOCATED;
 public:
-    LayoutRectRecorder(RenderObject&, bool skipRecording = false);
-    ~LayoutRectRecorder();
+    UnacceleratedImageBufferSurface(const IntSize&, OpacityMode = NonOpaque);
+    virtual ~UnacceleratedImageBufferSurface() { }
 
-    static bool shouldRecordLayoutRects();
+    virtual SkCanvas* canvas() const OVERRIDE { return m_canvas.get(); }
+    virtual bool isValid() const OVERRIDE { return m_canvas; }

[Stephen White, 2013/12/09 15:33:08]

Still not fond of an object that can be in an invalid state, but my
understanding is that these semantics are necessary for the mailbox
implementation in the layer bridge.

[Justin Novosad, 2013/12/09 16:37:31]

Actually, it is so that we can handle asynchronous graphics context losses.

 
 private:
-    RenderObject& m_object;
-    RenderLayerModelObject* m_repaintContainer;
-    unsigned m_skipRecording : 1;
+    OwnPtr<SkCanvas> m_canvas;
 };
 
 } // namespace WebCore
 
-#endif // LayoutRectRecorder_h
-
+#endif