Refactoring ImageBuffer to decouple it from Canvas2DLayerBridge

Source/core/html/canvas/WebGLRenderingContext.cpp

Index: Source/core/html/canvas/WebGLRenderingContext.cpp
diff --git a/Source/core/html/canvas/WebGLRenderingContext.cpp b/Source/core/html/canvas/WebGLRenderingContext.cpp
index 63c900aafe4a869b96bedfdf373cda3248e372f3..ae12477421e949bf0e5ab46fdc7450012a0203c7 100644
--- a/Source/core/html/canvas/WebGLRenderingContext.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContext.cpp
@@ -75,6 +75,7 @@
 #include "core/rendering/RenderBox.h"
 #include "platform/NotImplemented.h"
 #include "platform/geometry/IntSize.h"
+#include "platform/graphics/UnacceleratedImageBufferSurface.h"
 
 #include "wtf/PassOwnPtr.h"
 #include "wtf/Uint32Array.h"
@@ -5458,9 +5459,10 @@ ImageBuffer* WebGLRenderingContext::LRUImageBufferCache::imageBuffer(const IntSi
         return buf;
     }
 
-    OwnPtr<ImageBuffer> temp = ImageBuffer::create(size, 1);
-    if (!temp)
+    OwnPtr<ImageBufferSurface> surface = adoptPtr(new UnacceleratedImageBufferSurface(size));
+    if (!surface->isValid())

[Stephen White, 2013/12/04 21:18:40]

Do we need a null ptr check here?

         return 0;
+    OwnPtr<ImageBuffer> temp = adoptPtr(new ImageBuffer(surface.release()));
     i = std::min(m_capacity - 1, i);
     m_buffers[i] = temp.release();