Bug 539356 - Part 17 - Don't paint widgets that an invisible or empty bounds. r=roc

* * *
Bug 539356 - Part 13 - Only repaint widgets that have had changes since the last paint

widget/nsIWidget.h

@@ -1576,7 +1576,17 @@ class nsIWidget : public nsISupports {
       if (!mNeedsPaint) {
         return false;
       }
-      return true;
+
+      bool visible;
+      nsresult rv = IsVisible(visible);
+      NS_ENSURE_SUCCESS(rv, false);
+      if (!visible) {
+        return false;
+      }
+      nsIntRect bounds;
+      rv = GetBounds(bounds);
+      NS_ENSURE_SUCCESS(rv, false);
+      return !bounds.IsEmpty();
     }
 protected: