Remove duration from media::Clock.

media/base/clock.h

Index: media/base/clock.h
diff --git a/media/base/clock.h b/media/base/clock.h
index fbd7ca125d7d243922758b1e19db60654d29a394..791c9e69669d94237f2863ff4f9e7c16ef07b0c8 100644
--- a/media/base/clock.h
+++ b/media/base/clock.h
@@ -54,25 +54,14 @@ class MEDIA_EXPORT Clock {
   // Forcefully sets the media time to |current_time|. The second parameter is
   // the |max_time| that the clock should progress after a call to Play(). This
   // value is often the time of the end of the last frame buffered and decoded.
-  //
-  // These values are clamped to the duration of the video, which is initially
-  // set to 0 (before SetDuration() is called).
   void SetTime(base::TimeDelta current_time, base::TimeDelta max_time);
 
   // Sets the |max_time| to be returned by a call to Elapsed().
   void SetMaxTime(base::TimeDelta max_time);
 
-  // Returns the current elapsed media time. Returns 0 if SetDuration() has
-  // never been called.
+  // Returns the current elapsed media time.
   base::TimeDelta Elapsed();
 
-  // Sets the duration of the video. Clock expects the duration will be set
-  // exactly once.
-  void SetDuration(base::TimeDelta duration);
-
-  // Returns the duration of the clock, or 0 if not set.
-  base::TimeDelta Duration() const;
-
  private:
   // Updates the reference points based on the current calculated time.
   void UpdateReferencePoints();
@@ -113,9 +102,6 @@ class MEDIA_EXPORT Clock {
   // The maximum time that can be returned by calls to Elapsed().
   base::TimeDelta max_time_;
 
-  // Duration of the media.
-  base::TimeDelta duration_;
-
   DISALLOW_COPY_AND_ASSIGN(Clock);
 };