Give up focus if the focused view becomes unfocusable

ui/views/controls/button/text_button.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_CONTROLS_BUTTON_TEXT_BUTTON_H_
 #define UI_VIEWS_CONTROLS_BUTTON_TEXT_BUTTON_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 31 matching lines @@
   gfx::Insets insets_;
 
   DISALLOW_COPY_AND_ASSIGN(TextButtonBorder);
 };
 
 
 // A Border subclass that paints a TextButton's background layer -- basically
 // the button frame in the hot/pushed states.
 //
 // Note that this type of button is not focusable by default and will not be
-// part of the focus chain.  Call set_focusable(true) to make it part of the
+// part of the focus chain.  Call SetFocusable(true) to make it part of the
 // focus chain.
 class VIEWS_EXPORT TextButtonDefaultBorder : public TextButtonBorder {
  public:
   TextButtonDefaultBorder();
   virtual ~TextButtonDefaultBorder();
 
   // TextButtonDefaultBorder takes and retains ownership of these |painter|s.
   void set_normal_painter(Painter* painter) { normal_painter_.reset(painter); }
   void set_hot_painter(Painter* painter) { hot_painter_.reset(painter); }
   void set_pushed_painter(Painter* painter) { pushed_painter_.reset(painter); }
@@ skipping 318 matching lines @@
   // True if the button should ignore the minimum size for the platform. Default
   // is true. Set to false to prevent narrower buttons.
   bool ignore_minimum_size_;
 
   DISALLOW_COPY_AND_ASSIGN(TextButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_TEXT_BUTTON_H_