Add window overview mode behind --ash-enable-overview-mode flag to F5 key.

ash/ash.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,
     'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/chrome',
   },
   'includes': [
@@ skipping 460 matching lines @@
         'wm/window_animations.cc',
         'wm/window_animations.h',
         'wm/window_cycle_controller.cc',
         'wm/window_cycle_controller.h',
         'wm/window_cycle_list.cc',
         'wm/window_cycle_list.h',
         'wm/window_properties.cc',
         'wm/window_properties.h',
         'wm/window_resizer.cc',
         'wm/window_resizer.h',
+        'wm/window_selector.cc',
+        'wm/window_selector.h',
+        'wm/window_selector_controller.cc',
+        'wm/window_selector_controller.h',
+        'wm/window_selector_delegate.h',
         'wm/window_util.cc',
         'wm/window_util.h',
         'wm/workspace_controller.cc',
         'wm/workspace_controller.h',
         'wm/workspace/auto_window_management.cc',
         'wm/workspace/auto_window_management.h',
         'wm/workspace/colored_window_controller.cc',
         'wm/workspace/colored_window_controller.h',
         'wm/workspace/desktop_background_fade_controller.cc',
         'wm/workspace/desktop_background_fade_controller.h',
@@ skipping 244 matching lines @@
         'wm/sticky_keys_unittest.cc',
         'wm/system_gesture_event_filter_unittest.cc',
         'wm/system_modal_container_layout_manager_unittest.cc',
         'wm/toplevel_window_event_handler_unittest.cc',
         'wm/user_activity_detector_unittest.cc',
         'wm/video_detector_unittest.cc',
         'wm/window_animations_unittest.cc',
         'wm/window_cycle_controller_unittest.cc',
         'wm/window_manager_unittest.cc',
         'wm/window_modality_controller_unittest.cc',
+        'wm/window_selector_unittest.cc',
         'wm/window_util_unittest.cc',
         'wm/workspace_controller_test_helper.cc',
         'wm/workspace_controller_test_helper.h',
         'wm/workspace/magnetism_matcher_unittest.cc',
         'wm/workspace/multi_window_resize_controller_unittest.cc',
         'wm/workspace/workspace_event_handler_test_helper.cc',
         'wm/workspace/workspace_event_handler_test_helper.h',
         'wm/workspace/workspace_event_handler_unittest.cc',
         'wm/workspace/workspace_layout_manager_unittest.cc',
         'wm/workspace/workspace_manager_unittest.cc',
@@ skipping 150 matching lines @@
             'shell/cocoa/app-Info.plist',
           ],
           'xcode_settings': {
             'INFOPLIST_FILE': 'shell/cocoa/app-Info.plist',
           },
         }],
       ],
     },
   ],
 }