Animations: Introduce compositor AnimationPlayer and AnimationTimeline.

public/platform/WebCompositorAnimationPlayer.h

Index: public/platform/WebCompositorAnimationPlayer.h
diff --git a/public/platform/WebCompositorAnimationPlayer.h b/public/platform/WebCompositorAnimationPlayer.h
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+++ b/public/platform/WebCompositorAnimationPlayer.h
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+// Copyright 2015 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 WebCompositorAnimationPlayer_h
+#define WebCompositorAnimationPlayer_h
+
+namespace blink {
+
+class WebCompositorAnimation;
+class WebCompositorAnimationDelegate;
+class WebLayer;
+
+// A compositor representation for AnimationPlayer.
+class WebCompositorAnimationPlayer {
+public:
+    virtual ~WebCompositorAnimationPlayer() { }
+
+    // An animation delegate is notified when animations are started and
+    // stopped. The WebCompositorAnimationPlayer does not take ownership of the delegate, and it is
+    // the responsibility of the client to reset the layer's delegate before
+    // deleting the delegate.
+    virtual void setAnimationDelegate(WebCompositorAnimationDelegate*) = 0;
+
+    virtual void attachLayer(WebLayer*) = 0;
+    virtual void detachLayer() = 0;
+    virtual bool isLayerAttached() const = 0;
+
+    virtual void addAnimation(WebCompositorAnimation*) = 0;
+    virtual void removeAnimation(int animationId) = 0;
+    virtual void pauseAnimation(int animationId, double timeOffset) = 0;
+};
+
+} // namespace blink
+
+#endif // WebCompositorAnimationPlayer_h