Remove opaque alpha channel special case

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 324 matching lines @@
   // last frame needs to be decoded first.  Before calling this method, the
   // caller must verify that the frame exists.
   Vector<size_t> findFramesToDecode(size_t) const;
 
   // This is called by decode() after decoding a frame in an animated image.
   // Before calling this method, the caller must verify that the frame exists.
   // @return true  if the frame was fully decoded,
   //         false otherwise.
   bool postDecodeProcessing(size_t);
 
-  // The GIF and PNG decoders set the default alpha setting of the ImageFrame to
-  // true. When the frame rect does not contain any (semi-) transparent pixels,
-  // this may need to be changed to false. This depends on whether the required
-  // previous frame adds transparency to the image, outside of the frame rect.
-  // This methods corrects the alpha setting of the frame buffer to false when
-  // the whole frame is opaque.
-  //
-  // This method should be called by the GIF and PNG decoder when the pixels in
-  // the frame rect do *not* contain any transparent pixels. Before calling
-  // this method, the caller must verify that the frame exists.
-  void correctAlphaWhenFrameBufferSawNoAlpha(size_t);
-
   RefPtr<SegmentReader> m_data;  // The encoded data.
   Vector<ImageFrame, 1> m_frameBufferCache;
   const bool m_premultiplyAlpha;
   const ColorBehavior m_colorBehavior;
   ImageOrientation m_orientation;
 
   // The maximum amount of memory a decoded image should require. Ideally,
   // image decoders should downsample large images to fit under this limit
   // (and then return the downsampled size from decodedSize()). Ignoring
   // this limit can cause excessive memory use or even crashes on low-
@@ skipping 56 matching lines @@
   bool m_hasHistogrammedColorSpace = false;
 
   sk_sp<SkColorSpace> m_embeddedColorSpace = nullptr;
   bool m_sourceToTargetColorTransformNeedsUpdate = false;
   std::unique_ptr<SkColorSpaceXform> m_sourceToTargetColorTransform;
 };
 
 }  // namespace blink
 
 #endif