Have Player take the DocumentTimeline object by reference

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 19 matching lines @@
 
 
 #include "config.h"
 #include "core/animation/Player.h"
 
 #include "core/animation/DocumentTimeline.h"
 #include "core/animation/TimedItem.h"
 
 namespace WebCore {
 
-PassRefPtr<Player> Player::create(DocumentTimeline* timeline, TimedItem* content)
+PassRefPtr<Player> Player::create(DocumentTimeline& timeline, TimedItem* content)
 {
-    ASSERT(timeline);
     return adoptRef(new Player(timeline, content));
 }
 
-Player::Player(DocumentTimeline* timeline, TimedItem* content)
+Player::Player(DocumentTimeline& timeline, TimedItem* content)
     : m_pauseStartTime(nullValue())
     , m_playbackRate(1)
     , m_timeDrift(0)
-    , m_startTime(effectiveTime(timeline->currentTime()))
+    , m_startTime(effectiveTime(timeline.currentTime()))
     , m_content(content)
     , m_timeline(timeline)
     , m_isPausedForTesting(false)
 {
     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;
+    return (effectiveTime(m_timeline.currentTime()) - m_startTime) * m_playbackRate;
 }
 
 double Player::pausedTimeDrift() const
 {
     ASSERT(pausedInternal());
     return currentTimeBeforeDrift() - m_pauseStartTime;
 }
 
 double Player::timeDrift() const
 {
     return pausedInternal() ? pausedTimeDrift() : m_timeDrift;
 }
 
 double Player::currentTime() const
 {
     return currentTimeBeforeDrift() - timeDrift();
 }
 
 bool Player::update(double* timeToEffectChange)
 {
     if (!m_content) {
         if (timeToEffectChange)
             *timeToEffectChange = std::numeric_limits<double>::infinity();
         return false;
     }
 
-    double newTime = isNull(m_timeline->currentTime()) ? nullValue() : currentTime();
+    double newTime = isNull(m_timeline.currentTime()) ? nullValue() : currentTime();
     m_content->updateInheritedTime(newTime);
     if (timeToEffectChange)
         *timeToEffectChange = m_content->timeToEffectChange();
     return m_content->isCurrent() || m_content->isInEffect();
 }
 
 void Player::cancel()
 {
     if (!m_content)
         return;
@@ skipping 40 matching lines @@
 }
 
 void Player::setPlaybackRate(double newRate)
 {
     double previousTime = currentTime();
     m_playbackRate = newRate;
     setCurrentTime(previousTime);
 }
 
 } // namespace