views: add focus ring to TreeView

ui/views/controls/tree/tree_view.h

Index: ui/views/controls/tree/tree_view.h
diff --git a/ui/views/controls/tree/tree_view.h b/ui/views/controls/tree/tree_view.h
index 5eb096e3d2fb4f04d33cdfb68180c05f5342992f..108481f2d61f1361fcad785aff3e7a5c31d3d8e8 100644
--- a/ui/views/controls/tree/tree_view.h
+++ b/ui/views/controls/tree/tree_view.h
@@ -349,6 +349,10 @@ class VIEWS_EXPORT TreeView : public View,
   // control.
   bool IsPointInExpandControl(InternalNode* node, const gfx::Point& point);
 
+  // Returns the View that the focus ring for this TreeView should be drawn
+  // around.
+  View* FindFocusRingView();
+
   // The model, may be null.
   ui::TreeModel* model_;