Remove external BitmapImage lazy decoding tracking

Source/platform/graphics/FrameData.h

 /*
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2008-2009 Torch Mobile, Inc.
  *
  * 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 34 matching lines @@
     // Clear the cached image data on the frame, and (optionally) the metadata.
     // Returns whether there was cached image data to clear.
     bool clear(bool clearMetadata);
 
     RefPtr<SkImage> m_frame;
     ImageOrientation m_orientation;
     float m_duration;
     bool m_haveMetadata : 1;
     bool m_isComplete : 1;
     bool m_hasAlpha : 1;
-    bool m_isLazyDecoded : 1;
     size_t m_frameBytes;
 };
 
 } // namespace blink
 
 namespace WTF {
 template<> struct VectorTraits<blink::FrameData> : public SimpleClassVectorTraits<blink::FrameData> {
     static const bool canInitializeWithMemset = false; // Not all FrameData members initialize to 0.
 };
 }
 
 #endif // FrameData_h