Adding a new method that will allow caller to check if there pending events in the elder queue. r=sfraser@netscape.com, danm@netscape.com, b=76075

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()
 {

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();