Don't recreate SkImages for high-res (GIF, WEBP...) animations.

third_party/WebKit/Source/platform/graphics/BitmapImage.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 116 matching lines @@
 
     // Called before accessing m_frames[index]. Returns false on index out of bounds.
     bool ensureFrameIsCached(size_t index);
 
     // Returns the total number of bytes allocated for all framebuffers, i.e.
     // the sum of m_source.frameBytesAtIndex(...) for all frames.  This is
     // returned as an int for caller convenience, to allow safely subtracting
     // the values from successive calls as signed expressions.
     int totalFrameBytes();
 
-    // Called to invalidate cached data. When |destroyAll| is true, we wipe out
-    // the entire frame buffer cache and tell the image source to destroy
-    // everything; this is used when e.g. we want to free some room in the image
-    // cache. If |destroyAll| is false, we delete frames except the current
-    // frame; this is used while animating large images to keep memory footprint
-    // low; the decoder should preserve the current frame and may preserve some
-    // other frames to avoid redecoding the whole image on every frame.
-    void destroyDecodedData(bool destroyAll) override;
-
-    // If the image is large enough, calls destroyDecodedData().
-    void destroyDecodedDataIfNecessary();
+    // Called to wipe out the entire frame buffer cache and tell the image
+    // source to destroy everything; this is used when e.g. we want to free
+    // some room in the image cache.
+    void destroyDecodedData() override;
 
     // Notifies observers that the memory footprint has changed.
     void notifyMemoryChanged(int delta);
 
     // Whether or not size is available yet.
     bool isSizeAvailable();
 
     // Animation.
     int repetitionCount(bool imageKnownToBeComplete);  // |imageKnownToBeComplete| should be set if the caller knows the entire image has been decoded.
     bool shouldAnimate();
@@ skipping 31 matching lines @@
     bool m_sizeAvailable : 1; // Whether or not we can obtain the size of the first image frame yet from ImageIO.
     mutable bool m_hasUniformFrameSize : 1;
     mutable bool m_haveFrameCount : 1;
 };
 
 DEFINE_IMAGE_TYPE_CASTS(BitmapImage);
 
 } // namespace blink
 
 #endif