Add WebMediaPlayer::timelineOffset() support to WebMediaPlayerImpl.

media/base/demuxer.h

Index: media/base/demuxer.h
diff --git a/media/base/demuxer.h b/media/base/demuxer.h
index 31c9e29de504e0ad75ee2e19fb1af6f5e0c0f814..958be390b91984e2f9e0b3dbc0c19cc5fca3101f 100644
--- a/media/base/demuxer.h
+++ b/media/base/demuxer.h
@@ -87,6 +87,11 @@ class MEDIA_EXPORT Demuxer {
   // Returns the starting time for the media file.
   virtual base::TimeDelta GetStartTime() const = 0;
 
+  // Returns wallclock time represented by presentation timestamp 0.

[scherkus (not reviewing), 2014/04/15 00:53:40]

isn't it "wall clock" with a space, as in a clock that is on the wall?

also it's interesting that you use timeline_offset_ in numerous places without
the wallclock_ prefix, but have functions that do have Wallclock in there

how about side-stepping this whole bit by removing the words "wall clock"
everywhere since base::Time is by definition a wall clock time? (see
base/time/time.h)

[acolwell GONE FROM CHROMIUM, 2014/04/16 01:01:08]

Done.

+  // If the timstamps are not associated with a wallclock time, then
+  // a null Time is returned.
+  virtual base::Time GetWallclockTimelineOffset() const = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(Demuxer);
 };