diff --git a/mozilla/xpcom/threads/nsEventQueue.cpp b/mozilla/xpcom/threads/nsEventQueue.cpp
index df887abf4f0..aca9db61516 100644
--- a/mozilla/xpcom/threads/nsEventQueue.cpp
+++ b/mozilla/xpcom/threads/nsEventQueue.cpp
@@ -337,6 +337,19 @@ nsEventQueueImpl::IsQueueNative(PRBool *aResult)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsEventQueueImpl::PendingEvents(PRBool *aResult)
+{
+    *aResult = PL_EventAvailable(mEventQueue);
+    if (!*aResult && mElderQueue) {
+        nsCOMPtr<nsIEventQueue> elder(do_QueryInterface(mElderQueue));
+        if (elder)
+            return elder->EventAvailable(*aResult);
+    }
+    return NS_OK;
+}
+
+
 NS_IMETHODIMP
 nsEventQueueImpl::ProcessPendingEvents()
 {
diff --git a/mozilla/xpcom/threads/nsIEventQueue.idl b/mozilla/xpcom/threads/nsIEventQueue.idl
index 6bcb8d32fc1..f12135781c8 100644
--- a/mozilla/xpcom/threads/nsIEventQueue.idl
+++ b/mozilla/xpcom/threads/nsIEventQueue.idl
@@ -63,6 +63,7 @@ interface nsIEventQueue : nsISupports
     [noscript] void postSynchronousEvent(in PLEventPtr aEvent, 
                                          out voidPtr aResult);
 	
+    boolean pendingEvents();
     void processPendingEvents();
     void eventLoop();