Fixes focus traversal bug

ui/views/widget/widget_delegate.h

Index: ui/views/widget/widget_delegate.h
diff --git a/ui/views/widget/widget_delegate.h b/ui/views/widget/widget_delegate.h
index f465ffb3bc112f3762dc449402cea2df93c3f575..69c27317c7673a94082809c3678ad21a675d369c 100644
--- a/ui/views/widget/widget_delegate.h
+++ b/ui/views/widget/widget_delegate.h
@@ -159,6 +159,11 @@ class VIEWS_EXPORT WidgetDelegate {
   // Provides the hit-test mask if HasHitTestMask above returns true.
   virtual void GetWidgetHitTestMask(gfx::Path* mask) const;
 
+  // Returns true if focus should advance to the parent when tab/shift-tab is
+  // hit and on the last/first focusable view. Default returns false, which
+  // means tab/shift-tab never advance to the parent Widget.
+  virtual bool ShouldAdvanceFocusToParent() const;
+
   // Returns true if event handling should descend into |child|.
   // |location| is in terms of the Window.
   virtual bool ShouldDescendIntoChildForEventHandling(