Bug 257746 nsWindow::StandardWindowCreate should return failure when it can't create a window

patch by Chris Thomas (CTho) <cst@andrew.cmu.edu> r=ere sr=roc

widget/src/windows/nsWindow.cpp

@@ -1518,8 +1518,8 @@ nsWindow::StandardWindowCreate(nsIWidget *aParent,
                                       NULL);
   }
 
-  VERIFY(mWnd);
+  if (!mWnd)
-
+    return NS_ERROR_FAILURE;
 
   /*mNativeDragTarget = new nsNativeDragTarget(this);
   if (NULL != mNativeDragTarget) {