2D Canvas: Refactor code re-attempting to allocate an imageBuffer.

Source/core/html/HTMLCanvasElement.h

 /*
  * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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.
@@ skipping 102 matching lines @@
     SecurityOrigin* securityOrigin() const;
     void setOriginTainted() { m_originClean = false; }
     bool originClean() const { return m_originClean; }
 
     StyleResolver* styleResolver();
 
     AffineTransform baseTransform() const;
 
     bool is3D() const;
 
-    bool hasCreatedImageBuffer() const { return m_hasCreatedImageBuffer; }
+    bool hasImageBuffer() const { return m_imageBuffer.get(); }
 
     bool shouldAccelerate(const IntSize&) const;
 
     float deviceScaleFactor() const { return m_deviceScaleFactor; }
 
     InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
 
 private:
     explicit HTMLCanvasElement(Document&);
 
@@ skipping 23 matching lines @@
 
     bool m_ignoreReset;
     bool m_accelerationDisabled;
     FloatRect m_dirtyRect;
 
     intptr_t m_externallyAllocatedMemory;
 
     float m_deviceScaleFactor; // FIXME: This is always 1 and should probable be deleted
     bool m_originClean;
 
-    // m_createdImageBuffer means we tried to malloc the buffer.  We didn't necessarily get it.
-    mutable bool m_hasCreatedImageBuffer;
+    // It prevents HTMLCanvasElement::buffer() from continuously re-attempting to allocate an imageBuffer
+    // after the first attempt failed.
+    mutable bool m_didFailToCreateImageBuffer;
     mutable bool m_didClearImageBuffer;
     OwnPtr<ImageBuffer> m_imageBuffer;
     mutable OwnPtr<GraphicsContextStateSaver> m_contextStateSaver;
 
     mutable RefPtr<Image> m_presentedImage;
     mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
 };
 
 DEFINE_NODE_TYPE_CASTS(HTMLCanvasElement, hasTagName(HTMLNames::canvasTag));
 
 } //namespace
 
 #endif