Web Animations: Introduce ActiveAnimations and AnimationStack

Source/core/animation/Player.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 34 matching lines @@
 
 Player::Player(DocumentTimeline* timeline, TimedItem* content)
     : m_pauseStartTime(nullValue())
     , m_playbackRate(1)
     , m_timeDrift(0)
     , m_startTime(effectiveTime(timeline->currentTime()))
     , m_content(content)
     , m_timeline(timeline)
 {
     ASSERT(m_startTime >= 0);
+    if (m_content)
+        m_content->attach(this);
     update();
 }
 
+Player::~Player()
+{
+    if (m_content)
+        m_content->detach();
+}
+
 double Player::currentTimeBeforeDrift() const
 {
     return (effectiveTime(m_timeline->currentTime()) - m_startTime) * m_playbackRate;
 }
 
 double Player::pausedTimeDrift() const
 {
     ASSERT(paused());
     return currentTimeBeforeDrift() - m_pauseStartTime;
 }
@@ skipping 42 matching lines @@
 }
 
 void Player::setPlaybackRate(double newRate)
 {
     double previousTime = currentTime();
     m_playbackRate = newRate;
     setCurrentTime(previousTime);
 }
 
 } // namespace