Bug 1309516 part 2 - replace MediaFormatReader::DemuxStartTime() with MediaInfo::mStartTime; r=jya

MozReview-Commit-ID: JzO0Yv33ljL

--HG--
extra : rebase_source : e59bc8aa168dfda9ec5e41fd81bd98a2b9391663
extra : intermediate-source : cca0e5eaf29e7cfdc32f8b66e217e0d8fb0fd0ea
extra : source : 6af01ba877814a43b68bc004b0e28160216e7367

dom/media/MediaFormatReader.cpp

@@ -1965,27 +1965,13 @@ MediaFormatReader::SetSeekTarget(const SeekTarget& aTarget)
   // Transform the seek target time to the demuxer timeline.
   if (!ForceZeroStartTime()) {
     target.SetTime(aTarget.GetTime() - TimeUnit::FromMicroseconds(StartTime())
-                   + DemuxStartTime());
+                   + mInfo.mStartTime);
   }
 
   mOriginalSeekTarget = target;
   mFallbackSeekTime = mPendingSeekTime = Some(target.GetTime());
 }
 
-TimeUnit
-MediaFormatReader::DemuxStartTime()
-{
-  MOZ_ASSERT(OnTaskQueue());
-  MOZ_ASSERT(!ForceZeroStartTime());
-  MOZ_ASSERT(HasAudio() || HasVideo());
-
-  const TimeUnit startTime =
-    std::min(mAudio.mFirstDemuxedSampleTime.refOr(TimeUnit::FromInfinity()),
-             mVideo.mFirstDemuxedSampleTime.refOr(TimeUnit::FromInfinity()));
-
-  return startTime.IsInfinite() ? TimeUnit::FromMicroseconds(0) : startTime;
-}
-
 void
 MediaFormatReader::ScheduleSeek()
 {

dom/media/MediaFormatReader.h

@@ -553,7 +553,6 @@ private:
 
   // Seeking objects.
   void SetSeekTarget(const SeekTarget& aTarget);
-  media::TimeUnit DemuxStartTime();
   bool IsSeeking() const { return mPendingSeekTime.isSome(); }
   bool IsVideoSeeking() const
   {