Bug 1343754 - Label PLayerTransaction; r=bevistseng,kats

MozReview-Commit-ID: 8QF5SQKuFhY

--HG--
extra : rebase_source : c2dca1fff0e96489b87c704200a19a4b037c04f7

gfx/layers/ipc/CompositorBridgeChild.cpp

@@ -337,6 +337,17 @@ CompositorBridgeChild::AllocPLayerTransactionChild(const nsTArray<LayersBackend>
 {
   LayerTransactionChild* c = new LayerTransactionChild(aId);
   c->AddIPDLReference();
+
+  TabChild* tabChild = TabChild::GetFrom(c->GetId());
+
+  // Do the DOM Labeling.
+  if (tabChild) {
+    nsCOMPtr<nsIEventTarget> target =
+      tabChild->TabGroup()->EventTargetFor(TaskCategory::Other);
+    SetEventTargetForActor(c, target);
+    MOZ_ASSERT(c->GetActorEventTarget());
+  }
+
   return c;
 }