Make ui_controls only usable from interactive_ui_tests. This has two benefits:

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 265 matching lines @@
         'system/user/update_observer.h',
         'system/user/user_observer.h',
         'system/web_notification/web_notification_tray.cc',
         'system/web_notification/web_notification_tray.h',
         'tooltips/tooltip_controller.cc',
         'tooltips/tooltip_controller.h',
         'touch/touch_observer_hud.cc',
         'touch/touch_observer_hud.h',
         'touch/touch_uma.cc',
         'touch/touch_uma.h',
-        'ui_controls_ash.cc',
         'volume_control_delegate.h',
         'wm/app_list_controller.cc',
         'wm/app_list_controller.h',
         'wm/activation_controller.cc',
         'wm/activation_controller.h',
         'wm/activation_controller_delegate.h',
         'wm/always_on_top_controller.cc',
         'wm/always_on_top_controller.h',
         'wm/ash_activation_controller.cc',
         'wm/ash_activation_controller.h',
@@ skipping 442 matching lines @@
             'shell/cocoa/app-Info.plist',
           ],
           'xcode_settings': {
             'INFOPLIST_FILE': 'shell/cocoa/app-Info.plist',
           },
         }],
       ],
     },
   ],
 }