Bug 1302817 - r=jesup

MozReview-Commit-ID: 7uKiDvw1yf0

--HG--
extra : rebase_source : 0b34bf8859eaa47612c43986b0016c121ca222e4

dom/media/MediaStreamGraph.cpp

@@ -3955,7 +3955,7 @@ void
 MediaStreamGraphImpl::UnregisterCaptureStreamForWindow(uint64_t aWindowId)
 {
   MOZ_ASSERT(NS_IsMainThread());
-  for (uint32_t i = 0; i < mWindowCaptureStreams.Length(); i++) {
+  for (int32_t i = mWindowCaptureStreams.Length() - 1; i >= 0; i--) {
     if (mWindowCaptureStreams[i].mWindowId == aWindowId) {
       mWindowCaptureStreams.RemoveElementAt(i);
     }