Bug 1317576. Part 6 - ensure 'playbackEnded' is notified when seeking to the end on a paused media element. r=cpearce

MozReview-Commit-ID: 4fzru2oHaPV

--HG--
extra : rebase_source : 0c2c3e639ec360fe5826cd5bbcd2f0879fa3f158

dom/media/MediaDecoderStateMachine.cpp

@@ -1053,8 +1053,7 @@ public:
     // is restarted correctly.
     mMaster->StopPlayback();
 
-    if (mMaster->mPlayState == MediaDecoder::PLAY_STATE_PLAYING &&
-        !mSentPlaybackEndedEvent) {
+    if (!mSentPlaybackEndedEvent) {
       int64_t clockTime = std::max(mMaster->AudioEndTime(), mMaster->VideoEndTime());
       clockTime = std::max(int64_t(0), std::max(clockTime, mMaster->Duration().ToMicroseconds()));
       mMaster->UpdatePlaybackPosition(clockTime);
@@ -1507,6 +1506,12 @@ SeekingState::SeekCompleted()
     // once we download more data!
     AudioQueue().Finish();
     VideoQueue().Finish();
+
+    // We won't start MediaSink when paused. m{Audio,Video}Completed will
+    // remain false and 'playbackEnded' won't be notified. Therefore we
+    // need to set these flags explicitly when seeking to the end.
+    mMaster->mAudioCompleted = true;
+    mMaster->mVideoCompleted = true;
   }
 
   // We want to resolve the seek request prior finishing the first frame