Remove external BitmapImage lazy decoding tracking

Source/platform/graphics/DeferredImageDecoder.cpp

 /*
  * Copyright (C) 2012 Google Inc. 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 159 matching lines @@
 
 bool DeferredImageDecoder::frameIsCompleteAtIndex(size_t index) const
 {
     if (m_actualDecoder)
         return m_actualDecoder->frameIsCompleteAtIndex(index);
     if (index < m_frameData.size())
         return m_frameData[index].m_isComplete;
     return false;
 }
 
-bool DeferredImageDecoder::frameIsCachedAndLazyDecodedAtIndex(size_t index) const
-{
-    // All frames cached in m_frameData are lazy-decoded.
-    ASSERT(index >= m_frameData.size() || m_frameData[index].m_haveMetadata);
-    return index < m_frameData.size();
-}
-
 float DeferredImageDecoder::frameDurationAtIndex(size_t index) const
 {
     if (m_actualDecoder)
         return m_actualDecoder->frameDurationAtIndex(index);
     if (index < m_frameData.size())
         return m_frameData[index].m_duration;
     return 0;
 }
 
 size_t DeferredImageDecoder::frameBytesAtIndex(size_t index) const
@@ skipping 82 matching lines @@
     return image.release();
 }
 
 bool DeferredImageDecoder::hotSpot(IntPoint& hotSpot) const
 {
     // TODO: Implement.
     return m_actualDecoder ? m_actualDecoder->hotSpot(hotSpot) : false;
 }
 
 } // namespace blink