color: Add ColorCanvasExtensions runtime flag

third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef OffscreenCanvasRenderingContext2D_h
 #define OffscreenCanvasRenderingContext2D_h
 
 #include "core/html/canvas/CanvasContextCreationAttributes.h"
 #include "core/html/canvas/CanvasRenderingContext.h"
 #include "core/html/canvas/CanvasRenderingContextFactory.h"
@@ skipping 78 matching lines @@
   sk_sp<SkImageFilter> StateGetFilter() final;
   void SnapshotStateForFilter() final {}
 
   void ValidateStateStack() const final;
 
   bool HasAlpha() const final { return CreationAttributes().alpha(); }
   bool isContextLost() const override;
 
   ImageBitmap* TransferToImageBitmap(ScriptState*) final;
 
-  ColorBehavior DrawImageColorBehavior() const final;
-
  protected:
   OffscreenCanvasRenderingContext2D(
       ScriptState*,
       OffscreenCanvas*,
       const CanvasContextCreationAttributes& attrs);
   DECLARE_VIRTUAL_TRACE();
 
   virtual void NeedsFinalizeFrame() {
     CanvasRenderingContext::NeedsFinalizeFrame();
   }
@@ skipping 10 matching lines @@
 
 DEFINE_TYPE_CASTS(OffscreenCanvasRenderingContext2D,
                   CanvasRenderingContext,
                   context,
                   context->Is2d() && context->host(),
                   context.Is2d() && context.host());
 
 }  // namespace blink
 
 #endif  // OffscreenCanvasRenderingContext2D_h