Bug 1256510: When shutting down MediaStreamGraphs, if the graph hasn't started, let it start and shut down r=padenot

MozReview-Commit-ID: 64WjTbaduvu

dom/media/MediaStreamGraph.cpp

@@ -1479,6 +1479,14 @@ MediaStreamGraphImpl::ForceShutDown(ShutdownTicket* aShutdownTicket)
     MonitorAutoLock lock(mMonitor);
     mForceShutDown = true;
     mForceShutdownTicket = aShutdownTicket;
+    if (mLifecycleState == LIFECYCLE_THREAD_NOT_STARTED) {
+      // We *could* have just sent this a message to start up, so don't
+      // yank the rug out from under it.  Tell it to startup and let it
+      // shut down.
+      RefPtr<GraphDriver> driver = CurrentDriver();
+      MonitorAutoUnlock unlock(mMonitor);
+      driver->Start();
+    }
     EnsureNextIterationLocked();
   }
 }