Remove duplication of encoded image data

third_party/WebKit/Source/platform/graphics/BitmapImage.cpp

 /*
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2008 Apple 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
@@ skipping 100 matching lines @@
 
 void BitmapImage::destroyDecodedData()
 {
     m_cachedFrame.clear();
     for (size_t i = 0; i < m_frames.size(); ++i)
         m_frames[i].clear(true);
     m_source.clearCacheExceptFrame(kNotFound);
     notifyMemoryChanged();
 }
 
+PassRefPtr<SharedBuffer> BitmapImage::data()
+{
+    if (PassRefPtr<SharedBuffer> data = cachedData())

[haraken, 2016/06/23 01:26:41]

PassRefPtr<SharedBuffer> => RefPtr<SharedBuffer>

[hajimehoshi, 2016/06/23 09:23:12]

Done.

+        return data;
+    return m_source.data();
+}
+
+PassRefPtr<SharedBuffer> BitmapImage::cachedData()
+{
+    return Image::data();
+}
+
 void BitmapImage::notifyMemoryChanged()
 {
     if (getImageObserver())
         getImageObserver()->decodedSizeChangedTo(this, totalFrameBytes());
 }
 
 size_t BitmapImage::totalFrameBytes()
 {
     const size_t numFrames = frameCount();
     size_t totalBytes = 0;
@@ skipping 80 matching lines @@
         // cleared-on-a-previous-pass) frames!
         if (m_frames[i].m_haveMetadata && !m_frames[i].m_isComplete) {
             m_frames[i].clear(true);
             if (i == m_cachedFrameIndex)
                 m_cachedFrame.clear();
         }
     }
 
     // Feed all the data we've seen so far to the image decoder.
     m_allDataReceived = allDataReceived;
-    ASSERT(data());
-    m_source.setData(*data(), allDataReceived);
+    if (cachedData()) {
+        m_source.setData(*cachedData(), allDataReceived);
+        if (m_source.hasData()) {
+            resetEncodedImageData();

[haraken, 2016/06/23 01:26:40]

Add a comment and explain what this is doing and why it's important.

[hajimehoshi, 2016/06/23 09:23:13]

Done.

+            DCHECK(!cachedData());

[haraken, 2016/06/23 01:26:40]

Would it be clearer to rename cachedData to encodedImageData?

[hajimehoshi, 2016/06/23 09:23:13]

Hmm, I want to emphasize BitmapImage no longer has a cached encoded image data.
encodedImageData might be confusing. BTW resetEncodedImageData is also confusing
as the same reason, so I'll rename this.

+        }
+    }
 
     m_haveFrameCount = false;
     return isSizeAvailable();
 }
 
 bool BitmapImage::hasColorProfile() const
 {
     return m_source.hasColorProfile();
 }
 
@@ skipping 357 matching lines @@
 
     // We need to draw this frame if we advanced to it while not skipping, or if
     // while trying to skip frames we hit the last frame and thus had to stop.
     if (skippingFrames != advancedAnimation)
         getImageObserver()->animationAdvanced(this);
 
     return advancedAnimation;
 }
 
 } // namespace blink