Bug 1163924 - fix calculation of blockForStateMachineNotPlaying. r=roc.

dom/media/MediaDecoder.cpp

@@ -357,8 +357,7 @@ void MediaDecoder::UpdateStreamBlockingForStateMachinePlaying()
     return;
   }
   bool blockForStateMachineNotPlaying =
-    mDecoderStateMachine && !mDecoderStateMachine->IsPlaying() &&
-    mDecoderStateMachine->GetState() != MediaDecoderStateMachine::DECODER_STATE_COMPLETED;
+    mDecoderStateMachine && !mDecoderStateMachine->IsPlaying();
   if (blockForStateMachineNotPlaying != GetDecodedStream()->mHaveBlockedForStateMachineNotPlaying) {
     GetDecodedStream()->mHaveBlockedForStateMachineNotPlaying = blockForStateMachineNotPlaying;
     int32_t delta = blockForStateMachineNotPlaying ? 1 : -1;