Move gif image decoder to SkCodec

third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) Research In Motion Limited 2009-2010. 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 372 matching lines @@
   // This method indicates whether the provided frame has enough data to decode
   // successive frames that depend on it. It is used by clearCacheExceptFrame
   // to determine which frame to keep in cache when the indicated frame is not
   // yet sufficiently decoded.
   //
   // The default condition is that the frame status needs to be FramePartial or
   // FrameComplete, since the data of previous frames is copied in
   // initFrameBuffer() before setting the status to FramePartial. For WebP,
   // however, the status needs to be FrameComplete since the complete buffer is
   // used to do alpha blending in WEBPImageDecoder::applyPostProcessing().
+  // And gif is also treated differently, since it relies on SkCodec which
+  // requires the complete required previous frame.
   //
   // Before calling this, verify that frame |index| exists by checking that
   // |index| is smaller than |m_frameBufferCache|.size().
   virtual bool FrameStatusSufficientForSuccessors(size_t index) {
     DCHECK(index < frame_buffer_cache_.size());
     return frame_buffer_cache_[index].GetStatus() != ImageFrame::kFrameEmpty;
   }
 
  private:
   enum class SniffResult { JPEG, PNG, GIF, WEBP, ICO, BMP, kInvalid };
@@ skipping 25 matching lines @@
   bool has_histogrammed_color_space_ = false;
 
   sk_sp<SkColorSpace> embedded_color_space_ = nullptr;
   bool source_to_target_color_transform_needs_update_ = false;
   std::unique_ptr<SkColorSpaceXform> source_to_target_color_transform_;
 };
 
 }  // namespace blink
 
 #endif