Fixes focus traversal bug

ui/views/focus/focus_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_FOCUS_FOCUS_MANAGER_H_
 #define UI_VIEWS_FOCUS_FOCUS_MANAGER_H_
 
 #include <list>
 #include <map>
 
@@ skipping 290 matching lines @@
   // is enabled, the arrow key movement within grouped views are disabled.
   static void set_arrow_key_traversal_enabled(bool enabled) {
     arrow_key_traversal_enabled_ = enabled;
   }
   // Returns whether arrow key traversal is enabled.
   static bool arrow_key_traversal_enabled() {
     return arrow_key_traversal_enabled_;
   }
 
  private:
-  // Returns the next focusable view.
-  View* GetNextFocusableView(View* starting_view, bool reverse, bool dont_loop);
+  // Returns the next focusable view. Traversal starts at |starting_view|. If
+  // |starting_view| is NULL traversal starts at |starting_widget|. If both
+  // |starting_view| and |starting_widget| are NULL, traversal starts at
+  // |widget_|.
+  View* GetNextFocusableView(View* starting_view,
+                             Widget* starting_widget,
+                             bool reverse,
+                             bool dont_loop);
 
   // Returns the focusable view found in the FocusTraversable specified starting
   // at the specified view. This traverses down along the FocusTraversable
   // hierarchy.
   // Returns NULL if no focusable view were found.
   View* FindFocusableView(FocusTraversable* focus_traversable,
                           View* starting_view,
                           bool reverse);
 
   // Process arrow key traversal. Returns true if the event has been consumed
@@ skipping 31 matching lines @@
 
   // See description above getter.
   bool is_changing_focus_;
 
   DISALLOW_COPY_AND_ASSIGN(FocusManager);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_FOCUS_FOCUS_MANAGER_H_