Bug 1450266 P7 Make XMLHttpRequestMainThread check for a valid inner window before dispatching events. r=baku r=smaug

dom/xhr/XMLHttpRequestMainThread.cpp

@@ -1325,6 +1325,10 @@ XMLHttpRequestMainThread::DispatchOrStoreEvent(DOMEventTargetHelper* aTarget,
   MOZ_ASSERT(aTarget);
   MOZ_ASSERT(aEvent);
 
+  if (NS_FAILED(CheckInnerWindowCorrectness())) {
+    return;
+  }
+
   if (mEventDispatchingSuspended) {
     PendingEvent* event = mPendingEvents.AppendElement();
     event->mTarget = aTarget;
@@ -1352,6 +1356,10 @@ XMLHttpRequestMainThread::ResumeEventDispatching()
   nsTArray<PendingEvent> pendingEvents;
   pendingEvents.SwapElements(mPendingEvents);
 
+  if (NS_FAILED(CheckInnerWindowCorrectness())) {
+    return;
+  }
+
   for (uint32_t i = 0; i < pendingEvents.Length(); ++i) {
     bool dummy;
     pendingEvents[i].mTarget->DispatchEvent(pendingEvents[i].mEvent, &dummy);