aura: Allow creating content_shell without views.

ui/events/events.gyp

 # Copyright 2013 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 74 matching lines @@
         'x/events_x_utils.h',
         'x/touch_factory_x11.cc',
         'x/touch_factory_x11.h',
       ],
       'conditions': [
         ['use_aura==0 and toolkit_views==0', {
           'sources/': [
             ['exclude', '^gestures/*'],
           ]
         }],
-        ['toolkit_views==0', {
+        ['toolkit_views==0 and use_aura==0', {
           'sources!': [
             'event.cc',
             'event.h',
             'event_dispatcher.cc',
             'event_dispatcher.h',
             'event_handler.cc',
             'event_handler.h',
             'event_target.cc',
             'event_target.h',
           ],
         }],
         ['OS=="android"', {
           'sources!': [
             'event_utils.cc',
             'keycodes/keyboard_code_conversion.cc',
           ],
         }],
         ['use_x11==1', {
           'dependencies': [
             '<(DEPTH)/build/linux/system.gyp:x11',
           ],
         }],
       ],
     }
   ],
 }