Adding blink side flag that allows disabling YUV decoding

Source/web/WebSettingsImpl.h

Index: Source/web/WebSettingsImpl.h
diff --git a/Source/web/WebSettingsImpl.h b/Source/web/WebSettingsImpl.h
index 2ea737dcaf573df6f8c14fca46523cd2935cf254..9edda076e41b32d3d378f812955ef241344e4e0b 100644
--- a/Source/web/WebSettingsImpl.h
+++ b/Source/web/WebSettingsImpl.h
@@ -177,6 +177,7 @@ public:
     virtual void setWebSecurityEnabled(bool) OVERRIDE;
     virtual void setWideViewportQuirkEnabled(bool) OVERRIDE;
     virtual void setXSSAuditorEnabled(bool) OVERRIDE;
+    virtual void setYUVImageDecodingEnabled(bool); // FIXME: add OVERRIDE once this is in base class
 
     bool showFPSCounter() const { return m_showFPSCounter; }
     bool showPaintRects() const { return m_showPaintRects; }
@@ -217,6 +218,7 @@ private:
     // can be removed any time after 2015. See http://crbug.com/313754.
     bool m_clobberUserAgentInitialScaleQuirk;
     bool m_mainFrameResizesAreOrientationChanges;
+    bool m_yuvImageDecodingEnabled;
 };
 
 } // namespace blink