Re-introduce forward declaration of WebCompositorAnimation

cc/blink/web_to_cc_animation_delegate_adapter.h

 // Copyright 2014 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 CC_BLINK_WEB_TO_CC_ANIMATION_DELEGATE_ADAPTER_H_
 #define CC_BLINK_WEB_TO_CC_ANIMATION_DELEGATE_ADAPTER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "cc/animation/animation_delegate.h"
-#include "third_party/WebKit/public/platform/WebCompositorAnimationDelegate.h"
+
+namespace blink {
+class WebCompositorAnimationDelegate;
+}
 
 namespace cc_blink {
 
 class WebToCCAnimationDelegateAdapter : public cc::AnimationDelegate {
  public:
   explicit WebToCCAnimationDelegateAdapter(
       blink::WebCompositorAnimationDelegate* delegate);
 
  private:
   virtual void NotifyAnimationStarted(
       base::TimeTicks monotonic_time,
       cc::Animation::TargetProperty target_property) OVERRIDE;
   virtual void NotifyAnimationFinished(
       base::TimeTicks monotonic_time,
       cc::Animation::TargetProperty target_property) OVERRIDE;
 
   blink::WebCompositorAnimationDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(WebToCCAnimationDelegateAdapter);
 };
 
 }  // namespace cc_blink
 
 #endif  // CC_BLINK_WEB_TO_CC_ANIMATION_DELEGATE_ADAPTER_H_