Bug 978248. If the scrollframe has gone away just use the scroll offset that the APZC controller had instead of (0,0). r=botond

widget/xpwidgets/APZCCallbackHelper.cpp

@@ -99,7 +99,7 @@ ScrollFrameTo(nsIScrollableFrame* aFrame, const CSSPoint& aPoint, bool& aSuccess
   aSuccessOut = false;
 
   if (!aFrame) {
-    return CSSPoint();
+    return aPoint;
   }
 
   // If the scrollable frame is currently in the middle of an async or smooth