fixes bug 135547 "make event queues more robust"

r=danm sr=rpotts,brendan

xpcom/threads/nsEventQueue.cpp

@@ -386,6 +386,12 @@ nsEventQueueImpl::ProcessPendingEvents()
   }
 #endif
   PL_ProcessPendingEvents(mEventQueue);
+
+  // if we're no longer accepting events and there are still events in the
+  // queue, then process remaining events.
+  if (!mAcceptingEvents && PL_EventAvailable(mEventQueue))
+      PL_ProcessPendingEvents(mEventQueue);
+
   CheckForDeactivation();
 
   if (mElderQueue) {

xpcom/threads/nsEventQueueService.cpp

@@ -331,6 +331,7 @@ nsEventQueueServiceImpl::PopThreadEventQueue(nsIEventQueue *aQueue)
     ++gEventQueueLogCount;
 #endif
     aQueue->StopAcceptingEvents();
+    aQueue->ProcessPendingEvents(); // make sure we don't orphan any events
 
     if (aQueue == queue.get()) { // are we reomving the eldest queue?
       mEventQTable.Remove(&key); // remove nsIEventQueue from hash table (releases)