views: Factor out Listener from Combobox into its own header file.

views/views.gyp

 # Copyright (c) 2011 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.
 {
   'variables': {
     'chromium_code': 1,
   },
 
   'target_defaults': {
     'conditions': [
@@ skipping 57 matching lines @@
         'controls/button/image_button.cc',
         'controls/button/image_button.h',
         'controls/button/menu_button.cc',
         'controls/button/menu_button.h',
         'controls/button/radio_button.cc',
         'controls/button/radio_button.h',
         'controls/button/text_button.cc',
         'controls/button/text_button.h',
         'controls/combobox/combobox.cc',
         'controls/combobox/combobox.h',
+        'controls/combobox/combobox_listener.h',
         'controls/combobox/native_combobox_gtk.cc',
         'controls/combobox/native_combobox_gtk.h',
         'controls/combobox/native_combobox_views.cc',
         'controls/combobox/native_combobox_views.h',
         'controls/combobox/native_combobox_win.cc',
         'controls/combobox/native_combobox_win.h',
         'controls/combobox/native_combobox_wrapper.h',
         'controls/focusable_border.cc',
         'controls/focusable_border.h',
         'controls/image_view.cc',
@@ skipping 632 matching lines @@
           },
           'sources': [
             '../ui/views/examples/table_example.cc',
             '../ui/views/examples/table_example.h',
           ],
         }],
       ],
     },
   ],
 }