Implement app list folder management page UI.

ui/app_list/app_list.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 60 matching lines @@
         'search_box_model.cc',
         'search_box_model.h',
         'search_box_model_observer.h',
         'search_result.cc',
         'search_result.h',
         'signin_delegate.cc',
         'signin_delegate.h',
         'views/app_list_background.cc',
         'views/app_list_background.h',
         'views/app_list_drag_and_drop_host.h',
+        'views/app_list_folder_view.cc',
+        'views/app_list_folder_view.h',
         'views/app_list_item_view.cc',
         'views/app_list_item_view.h',
         'views/app_list_main_view.cc',
         'views/app_list_main_view.h',
         'views/app_list_menu_views.cc',
         'views/app_list_menu_views.h',
         'views/app_list_view.cc',
         'views/app_list_view.h',
         'views/apps_grid_view.cc',
         'views/apps_grid_view.h',
         'views/apps_grid_view_delegate.h',
         'views/cached_label.cc',
         'views/cached_label.h',
         'views/contents_view.cc',
         'views/contents_view.h',
+        'views/folder_header_view.cc',
+        'views/folder_header_view.h',
         'views/page_switcher.cc',
         'views/page_switcher.h',
         'views/progress_bar_view.cc',
         'views/progress_bar_view.h',
         'views/pulsing_block_view.cc',
         'views/pulsing_block_view.h',
         'views/search_box_view.cc',
         'views/search_box_view.h',
         'views/search_box_view_delegate.h',
         'views/search_result_actions_view.cc',
@@ skipping 114 matching lines @@
             '../../webkit/glue/webkit_glue.gyp:glue',
             '../../webkit/glue/webkit_glue.gyp:glue_child',
           ],
         }],
       ],
       # Disable c4267 warnings until we fix size_t to int truncations.
       'msvs_disabled_warnings': [ 4267, ],
     },
   ],
 }