Revert of Animations: Disable compositor when timeline playback rate is set

Source/core/animation/AnimationPlayer.cpp

 /*
  * 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 581 matching lines @@
 
 void AnimationPlayer::setOutdated()
 {
     m_outdated = true;
     if (m_timeline)
         m_timeline->setOutdatedAnimationPlayer(this);
 }
 
 bool AnimationPlayer::canStartAnimationOnCompositor()
 {
-    // FIXME: Timeline playback rates should be compositable
-    if (m_playbackRate == 0 || (std::isinf(sourceEnd()) && m_playbackRate < 0) || (timeline() && timeline()->playbackRate() != 1))
+    if (m_playbackRate == 0 || (std::isinf(sourceEnd()) && m_playbackRate < 0))
         return false;
 
     return m_timeline && m_content && m_content->isAnimation() && playing();
 }
 
 bool AnimationPlayer::maybeStartAnimationOnCompositor()
 {
     if (!canStartAnimationOnCompositor())
         return false;
 
@@ skipping 206 matching lines @@
 
 void AnimationPlayer::trace(Visitor* visitor)
 {
     visitor->trace(m_content);
     visitor->trace(m_timeline);
     visitor->trace(m_pendingFinishedEvent);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace