Bug 1177466 - Clean up places calling MaybeStartPlayback() in MediaDecoderStateMachine. r=cpearce

dom/media/MediaDecoderStateMachine.cpp

@@ -2365,7 +2365,6 @@ MediaDecoderStateMachine::FinishDecodeFirstFrame()
   // So we need to check if this has occurred, else our decode pipeline won't
   // run (since it doesn't need to) and we won't detect end of stream.
   CheckIfDecodeComplete();
-  MaybeStartPlayback();
 
   if (mQueuedSeek.Exists()) {
     mPendingSeek.Steal(mQueuedSeek);
@@ -2933,12 +2932,6 @@ void MediaDecoderStateMachine::AdvanceFrame()
     }
   }
 
-  // We've got enough data to keep playing until at least the next frame.
-  // Start playing now if need be.
-  if ((mFragmentEndTime >= 0 && clock_time < mFragmentEndTime) || mFragmentEndTime < 0) {
-    MaybeStartPlayback();
-  }
-
   // Cap the current time to the larger of the audio and video end time.
   // This ensures that if we're running off the system clock, we don't
   // advance the clock to after the media end time.