Web Animations API: Start implementation of Element.animate().

Source/core/animation/DocumentTimeline.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 66 matching lines @@
     size_t numberOfActiveAnimationsForTesting() const;
 
     void addEventToDispatch(EventTarget* target, PassRefPtr<Event> event)
     {
         m_events.append(EventToDispatch(target, event));
     }
 
     void dispatchEvents();
     void dispatchEventsAsync();
 
+    const Vector<RefPtr<Player> > players() const { return m_players; }
+
 protected:
     DocumentTimeline(Document*, PassOwnPtr<PlatformTiming>);
 
 private:
     double m_zeroTime;
     Document* m_document;
     Timer<DocumentTimeline> m_eventDistpachTimer;
     Vector<RefPtr<Player> > m_players;
 
     void eventDispatchTimerFired(Timer<DocumentTimeline>*);
@@ skipping 34 matching lines @@
         Timer<DocumentTimelineTiming> m_timer;
 
     };
 
     friend class AnimationDocumentTimelineTest;
 };
 
 } // namespace
 
 #endif