Backing out bug 493109 on suspicion of causing crashes in linux tests

content/media/video/src/nsOggDecoder.cpp

@@ -1141,6 +1141,15 @@ void nsOggDecodeStateMachine::Shutdown()
     mBufferExhausted = PR_FALSE;
     oggplay_prepare_for_close(mPlayer);
   }
+  if (mStepDecodeThread) {
+    // nsOggDecodeStateMachine::Shutdown is called at a safe
+    // time to spin the event loop. This makes the following call
+    // also safe.
+    mon.Exit();
+    mStepDecodeThread->Shutdown();
+    mon.Enter();
+    mStepDecodeThread = nsnull;
+  }
 }
 
 void nsOggDecodeStateMachine::Decode()
@@ -1178,19 +1187,6 @@ nsresult nsOggDecodeStateMachine::Run()
       if (mPlaying) {
         StopPlayback();
       }
-      // Ensure mStepDecodeThread exits
-      if (mStepDecodeThread) {
-        mDecodingCompleted = PR_TRUE;
-        mBufferExhausted = PR_FALSE;
-        mon.NotifyAll();
-
-        mon.Exit();
-        mStepDecodeThread->Shutdown();
-        mon.Enter();
-        NS_ASSERTION(mState == DECODER_STATE_SHUTDOWN,
-                     "How did we escape from the shutdown state???");
-        mStepDecodeThread = nsnull;
-      }
       return NS_OK;
 
     case DECODER_STATE_DECODING_METADATA:
@@ -1284,9 +1280,6 @@ nsresult nsOggDecodeStateMachine::Run()
           mDecodingCompleted = PR_FALSE;
           mBufferExhausted = PR_FALSE;
           mon.NotifyAll();
-          // We can call Shutdown here without releasing our monitor
-          // because mStepDecodeThread has already exited
-          // nsOggStepDecodeEvent.
           mStepDecodeThread->Shutdown();
           mStepDecodeThread = nsnull;
           continue;
@@ -1818,13 +1811,11 @@ public:
 
   NS_IMETHOD Run() {
     NS_ASSERTION(NS_IsMainThread(), "Should be called on main thread");
-
     // The decode thread must die before the state machine can die.
     // The state machine must die before the reader.
     // The state machine must die before the decoder.
     if (mDecodeThread)
       mDecodeThread->Shutdown();
-
     mDecodeThread = nsnull;
     mDecodeStateMachine = nsnull;
     mReader = nsnull;
@@ -1883,6 +1874,7 @@ void nsOggDecoder::Stop()
                                                           mDecodeThread);
   NS_DispatchToMainThread(event, NS_DISPATCH_NORMAL);
 
+  // Null data fields. They can be reinitialized in future Load()s safely now.
   mDecodeThread = nsnull;
   mDecodeStateMachine = nsnull;
   UnregisterShutdownObserver();