Web Animations: Fix Player's timing update when source content becomes longer

Source/core/animation/AnimationPlayer.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 64 matching lines @@
     //  n         - if this player requires an update after 'n' units of time
     double timeToEffectChange();
 
     void cancel();
 
     double currentTime(bool& isNull);
     double currentTime();
     void setCurrentTime(double newCurrentTime);
 
     double currentTimeInternal() const;
+    double unlimitedCurrentTimeInternal() const;
 
     void setCurrentTimeInternal(double newCurrentTime, TimingUpdateReason = TimingUpdateOnDemand);
     bool paused() const { return m_paused && !m_isPausedForTesting; }
     static const char* playStateString(AnimationPlayState);
     String playState() const { return playStateString(playStateInternal()); }
     AnimationPlayState playStateInternal() const;
 
     void pause();
     void play();
     void reverse();
@@ skipping 169 matching lines @@
     int m_compositorGroup;
 
     bool m_currentTimePending;
     bool m_stateIsBeingUpdated;
 
 };
 
 } // namespace blink
 
 #endif // AnimationPlayer_h