Make platform/image-decoders to use USING_FAST_MALLOC.

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
@@ skipping 14 matching lines @@
 
 #ifndef PNGImageDecoder_h
 #define PNGImageDecoder_h
 
 #include "platform/image-decoders/ImageDecoder.h"
 
 namespace blink {
 
 class PNGImageReader;
 
-class PLATFORM_EXPORT PNGImageDecoder : public ImageDecoder {
+class PLATFORM_EXPORT PNGImageDecoder final : public ImageDecoder {
     WTF_MAKE_NONCOPYABLE(PNGImageDecoder);
 public:
     PNGImageDecoder(AlphaOption, GammaAndColorProfileOption, size_t maxDecodedBytes, unsigned offset = 0);
     ~PNGImageDecoder() override;
 
     // ImageDecoder:
     String filenameExtension() const override { return "png"; }
     bool hasColorProfile() const override { return m_hasColorProfile; }
 
     // Callbacks from libpng
@@ skipping 12 matching lines @@
     void decode(bool onlySize);
 
     OwnPtr<PNGImageReader> m_reader;
     bool m_hasColorProfile;
     const unsigned m_offset;
 };
 
 } // namespace blink
 
 #endif