Bug 1219403 - Account for the fact that MediaStream::Destroy can be run safely

on the main thread during shutdown.

--HG--
extra : rebase_source : e1d3b8bc0f97a885d289b6abfb493238222fcba7

dom/media/MediaStreamGraph.cpp

@@ -2417,7 +2417,7 @@ MediaInputPort::Init()
 void
 MediaInputPort::Disconnect()
 {
-  MOZ_ASSERT(GraphImpl()->CurrentDriver()->OnThread());
+  MOZ_ASSERT(GraphImpl()->AssertOnGraphThreadOrNotRunning());
   NS_ASSERTION(!mSource == !mDest,
                "mSource must either both be null or both non-null");
   if (!mSource)