Adding blink side flag that allows disabling YUV decoding

Source/platform/graphics/DecodingImageGenerator.cpp

 /*
  * Copyright (C) 2012 Google 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
@@ skipping 17 matching lines @@
 
 #include "SkData.h"
 #include "SkImageInfo.h"
 #include "platform/PlatformInstrumentation.h"
 #include "platform/SharedBuffer.h"
 #include "platform/TraceEvent.h"
 #include "platform/graphics/ImageFrameGenerator.h"
 
 namespace blink {
 
+bool DecodingImageGenerator::s_decodeToYUVEnabled = false;
+
+void DecodingImageGenerator::setDecodeToYUVEnabled(bool enabled)
+{
+    s_decodeToYUVEnabled = enabled;
+}
+
+bool DecodingImageGenerator::decodeToYUVEnabled()
+{
+    return s_decodeToYUVEnabled;
+}
+
 DecodingImageGenerator::DecodingImageGenerator(PassRefPtr<ImageFrameGenerator> frameGenerator, const SkImageInfo& info, size_t index)
     : m_frameGenerator(frameGenerator)
     , m_imageInfo(info)
     , m_frameIndex(index)
     , m_generationId(0)
 {
 }
 
 DecodingImageGenerator::~DecodingImageGenerator()
 {
@@ skipping 30 matching lines @@
     }
 
     PlatformInstrumentation::willDecodeLazyPixelRef(m_generationId);
     bool decoded = m_frameGenerator->decodeAndScale(m_imageInfo, m_frameIndex, pixels, rowBytes);
     PlatformInstrumentation::didDecodeLazyPixelRef();
     return decoded;
 }
 
 bool DecodingImageGenerator::onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], SkYUVColorSpace* colorSpace)
 {
-    if (!planes || !planes[0]) {
+    if (!decodeToYUVEnabled())
+        return false;
+
+    if (!planes || !planes[0])
         return m_frameGenerator->getYUVComponentSizes(sizes);
-    }
 
     TRACE_EVENT0("blink", "DecodingImageGenerator::onGetYUV8Planes");
     PlatformInstrumentation::willDecodeLazyPixelRef(m_generationId);
     bool decoded = m_frameGenerator->decodeToYUV(sizes, planes, rowBytes);
     PlatformInstrumentation::didDecodeLazyPixelRef();
     if (colorSpace)
         *colorSpace = kJPEG_SkYUVColorSpace;
     return decoded;
 }
 
 } // namespace blink