Animations: Introduce compositor AnimationPlayer and AnimationTimeline.

Source/core/animation/AnimationPlayer.h

Index: Source/core/animation/AnimationPlayer.h
diff --git a/Source/core/animation/AnimationPlayer.h b/Source/core/animation/AnimationPlayer.h
index d9e23f50270e37e2b3f36e6c7d86b064221e7f71..81b6443058938a8c84a2aa8344d0aead2602ecd0 100644
--- a/Source/core/animation/AnimationPlayer.h
+++ b/Source/core/animation/AnimationPlayer.h
@@ -39,6 +39,8 @@
 #include "core/dom/DOMException.h"
 #include "core/events/EventTarget.h"
 #include "platform/heap/Handle.h"
+#include "public/platform/WebCompositorAnimationDelegate.h"
+#include "public/platform/WebCompositorAnimationPlayerClient.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
@@ -46,11 +48,14 @@ namespace blink {
 class AnimationTimeline;
 class Element;
 class ExceptionState;
+class WebCompositorAnimationPlayer;
 
 class AnimationPlayer final
     : public EventTargetWithInlineData
     , public RefCountedWillBeNoBase<AnimationPlayer>
-    , public ActiveDOMObject {
+    , public ActiveDOMObject
+    , public WebCompositorAnimationDelegate
+    , public WebCompositorAnimationPlayerClient {
     DEFINE_WRAPPERTYPEINFO();
     REFCOUNTED_EVENT_TARGET(AnimationPlayer);
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(AnimationPlayer);
@@ -140,7 +145,8 @@ public:
     void setOutdated();
     bool outdated() { return m_outdated; }
 
-    bool canStartAnimationOnCompositor();
+    bool canStartAnimationOnCompositor() const;
+    bool isCandidateForAnimationOnCompositor() const;
     bool maybeStartAnimationOnCompositor();
     void cancelAnimationOnCompositor();
     void restartAnimationOnCompositor();
@@ -149,6 +155,8 @@ public:
     void setCompositorPending(bool sourceChanged = false);
     void notifyCompositorStartTime(double timelineTime);
     void notifyStartTime(double timelineTime);
+    // WebCompositorAnimationPlayerClient implementation.
+    WebCompositorAnimationPlayer* compositorPlayer() const override { return m_compositorPlayer.get(); }
 
     bool affects(const Element&, CSSPropertyID) const;
 
@@ -183,6 +191,16 @@ private:
     void beginUpdatingState();
     void endUpdatingState();
 
+    void createCompositorPlayer();
+    void destroyCompositorPlayer();
+    void attachCompositorTimeline();
+    void detachCompositorTimeline();
+    void attachCompositedLayers();
+    void detachCompositedLayers();
+    // WebCompositorAnimationDelegate implementation.
+    void notifyAnimationStarted(double monotonicTime, int group) override;
+    void notifyAnimationFinished(double monotonicTime, int group) override { }
+
     AnimationPlayState m_playState;
     double m_playbackRate;
     double m_startTime;
@@ -258,9 +276,10 @@ private:
     bool m_compositorPending;
     int m_compositorGroup;
 
+    OwnPtr<WebCompositorAnimationPlayer> m_compositorPlayer;
+
     bool m_currentTimePending;
     bool m_stateIsBeingUpdated;
-
 };
 
 } // namespace blink