Refactor ImageBuffer to make OffscreenCanvas match HTMLCanvasElement

third_party/WebKit/Source/core/html/canvas/CanvasRenderingContextHost.h

 // Copyright 2017 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 CanvasRenderingContextHost_h
 #define CanvasRenderingContextHost_h
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "core/CoreExport.h"
 #include "core/events/EventDispatcher.h"
 #include "core/events/EventTarget.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/IntSize.h"
+#include "platform/graphics/ImageBuffer.h"
 #include "platform/heap/GarbageCollected.h"
 
 namespace blink {
 
 class StaticBitmapImage;
 class KURL;
 
 class CORE_EXPORT CanvasRenderingContextHost : public GarbageCollectedMixin {
  public:
   CanvasRenderingContextHost();
@@ skipping 11 matching lines @@
 
   virtual ExecutionContext* GetTopExecutionContext() const = 0;
   virtual DispatchEventResult HostDispatchEvent(Event*) = 0;
   virtual const KURL& GetExecutionContextUrl() const = 0;
 
   virtual ScriptPromise Commit(RefPtr<StaticBitmapImage>,
                                bool is_web_gl_software_rendering,
                                ScriptState*,
                                ExceptionState&);
 
+  virtual void DiscardImageBuffer() = 0;
+  virtual ImageBuffer* GetImageBuffer() const = 0;
+  virtual ImageBuffer* GetOrCreateImageBuffer() = 0;
+
   // TODO(fserb): remove this.
   virtual bool IsOffscreenCanvas() const { return false; }
 
  protected:
   virtual ~CanvasRenderingContextHost() {}
 };
 
 }  // namespace blink
 
 #endif  // CanvasRenderingContextHost_h