Web Animations: Plumb compositor group id through animation creation and start/finish notifications

public/platform/WebCompositorAnimationDelegate.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 WebCompositorAnimationDelegate_h
 #define WebCompositorAnimationDelegate_h
 
 #include "WebCommon.h"
 #include "WebCompositorAnimation.h"
 
-#define WEB_ANIMATION_DELEGATE_TAKES_MONOTONIC_TIME 1
+#define WEB_COMPOSITOR_ANIMATION_DELEGATE_TAKES_GROUP 1
 
 namespace blink {
 
 class BLINK_PLATFORM_EXPORT WebCompositorAnimationDelegate {
 public:
     virtual ~WebCompositorAnimationDelegate() { }
 
-    virtual void notifyAnimationStarted(double monotonicTime, WebCompositorAnimation::TargetProperty) = 0;
-    virtual void notifyAnimationFinished(double monotonicTime, WebCompositorAnimation::TargetProperty) = 0;
+    virtual void notifyAnimationStarted(double monotonicTime, int group) = 0;
+    virtual void notifyAnimationFinished(double monotonicTime, int group) = 0;
 };
 
 } // namespace blink
 
 #endif // WebCompositorAnimationDelegate_h