344701 Leaking nsMacWindow objects for top-level windows. r=josh

widget/src/mac/nsWindow.cpp

@@ -576,8 +576,8 @@ static Boolean we_are_front_process()
 //-------------------------------------------------------------------------
 NS_IMETHODIMP nsWindow::SetFocus(PRBool aRaise)
 {
-  nsIWidget* top;
-  nsToolkit::GetTopWidget(mWindowPtr, &top);
+  nsCOMPtr<nsIWidget> top;
+  nsToolkit::GetTopWidget(mWindowPtr, getter_AddRefs(top));
 
   if (top) {
     nsCOMPtr<nsPIWidgetMac> topMac = do_QueryInterface(top);
@@ -2312,7 +2312,7 @@ NS_IMETHODIMP nsWindow::GetAttention(PRInt32 aCycleCount)
 	gNMRec.nmSound  = NULL;   // No alert sound, see bug 307323
 	gNMRec.nmStr    = NULL;   // No alert/window so no text
 	gNMRec.nmResp   = NULL;   // No response proc, use the default behavior
-	gNMRec.nmRefCon = NULL;
+	gNMRec.nmRefCon = 0;
 	if (::NMInstall(&gNMRec) == noErr)
 		gNotificationInstalled = true;