Web Animations: Sort Animations in the AnimationStack

Source/core/animation/DocumentTimeline.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 62 matching lines @@
     RefPtr<AnimationPlayer> player = AnimationPlayer::create(*this, child);
     AnimationPlayer* result = player.get();
     m_players.add(result);
     setOutdatedAnimationPlayer(result);
     return result;
 }
 
 AnimationPlayer* DocumentTimeline::play(TimedItem* child)
 {
     AnimationPlayer* player = createAnimationPlayer(child);
-    player->setStartTime(currentTime());
+    player->setStartTime(effectiveTime());
     return player;
 }
 
 void DocumentTimeline::wake()
 {
     m_timing->serviceOnNextFrame();
 }
 
 void DocumentTimeline::serviceAnimations()
 {
@@ skipping 50 matching lines @@
         m_timeline->m_document->view()->scheduleAnimation();
 }
 
 double DocumentTimeline::currentTime()
 {
     if (!m_document)
         return std::numeric_limits<double>::quiet_NaN();
     return m_document->animationClock().currentTime() - m_zeroTime;
 }
 
+double DocumentTimeline::effectiveTime()
+{
+    double time = currentTime();
+    return std::isnan(time) ? 0 : time;
+}
+
 void DocumentTimeline::pauseAnimationsForTesting(double pauseTime)
 {
     for (HashSet<RefPtr<AnimationPlayer> >::iterator it = m_playersNeedingUpdate.begin(); it != m_playersNeedingUpdate.end(); ++it)
         (*it)->pauseForTesting(pauseTime);
     serviceAnimations();
 }
 
 void DocumentTimeline::setOutdatedAnimationPlayer(AnimationPlayer* player)
 {
     m_playersNeedingUpdate.add(player);
@@ skipping 17 matching lines @@
             count += (timedItem && (timedItem->isCurrent() || timedItem->isInEffect()));
     }
     return count;
 }
 
 void DocumentTimeline::detachFromDocument() {
     m_document = 0;
 }
 
 } // namespace