Add support for Animated PNG

third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.h

 /*
  * Copyright (C) 2006 Apple Computer, 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
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef PNGImageDecoder_h
 #define PNGImageDecoder_h
 
+#include <memory>
 #include "platform/image-decoders/ImageDecoder.h"
-#include <memory>
+#include "platform/image-decoders/png/PNGImageReader.h"
 
 namespace blink {
 
-class PNGImageReader;
-
 class PLATFORM_EXPORT PNGImageDecoder final : public ImageDecoder {
   WTF_MAKE_NONCOPYABLE(PNGImageDecoder);
 
  public:
   PNGImageDecoder(AlphaOption,
                   const ColorBehavior&,
                   size_t maxDecodedBytes,
                   size_t offset = 0);
   ~PNGImageDecoder() override;
 
   // ImageDecoder:
   String filenameExtension() const override { return "png"; }
+  int repetitionCount() const override;
+  bool frameIsCompleteAtIndex(size_t) const override;
+  float frameDurationAtIndex(size_t) const override;
+  bool setFailed() override;
 
   // Callbacks from libpng
   void headerAvailable();
   void rowAvailable(unsigned char* row, unsigned rowIndex, int);
-  void complete();
+  void frameComplete();
+
+  void setRepetitionCount(int);
 
  private:
+  using ParseQuery = PNGImageReader::ParseQuery;
+
   // ImageDecoder:
-  void decodeSize() override { decode(true); }
-  void decode(size_t) override { decode(false); }
-
-  // Decodes the image.  If |onlySize| is true, stops decoding after
-  // calculating the image size.  If decoding fails but there is no more
-  // data coming, sets the "decode failure" flag.
-  void decode(bool onlySize);
+  void decodeSize() override { parse(ParseQuery::Size); }
+  void decode(size_t) override;
+  void parse(ParseQuery);
+  size_t decodeFrameCount() override;
+  void initializeNewFrame(size_t) override;
+  void clearFrameBuffer(size_t) override;
+  bool canReusePreviousFrameBuffer(size_t) const override;
 
   std::unique_ptr<PNGImageReader> m_reader;
   const unsigned m_offset;
+  size_t m_currentFrame;
+  int m_repetitionCount;
+  bool m_hasAlphaChannel;
+  bool m_currentBufferSawAlpha;
 };
 
 }  // namespace blink
 
 #endif