Restructure the events target into two components:

ui/aura/aura.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': [
     {
       'target_name': 'aura',
       'type': '<(component)',
       'dependencies': [
         '../../base/base.gyp:base',
         '../../base/base.gyp:base_i18n',
         '../../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         '../../cc/cc.gyp:cc',
         '../../gpu/gpu.gyp:gpu',
         '../../skia/skia.gyp:skia',
         '../compositor/compositor.gyp:compositor',
         '../events/events.gyp:events',
+        '../events/events.gyp:events_base',
         '../gfx/gfx.gyp:gfx',
         '../ui.gyp:ui',
         '../ui.gyp:ui_resources',
       ],
       'defines': [
         'AURA_IMPLEMENTATION',
       ],
       'sources': [
         'client/activation_change_observer.h',
         'client/activation_change_observer.cc',
@@ skipping 86 matching lines @@
         }],
         ['OS=="win"', {
           'dependencies': [
             '../metro_viewer/metro_viewer.gyp:metro_viewer_messages',
             '../../ipc/ipc.gyp:ipc',
           ],
           'sources!': [
             'input_state_lookup.cc',
           ],
         }],
-        ['use_ozone==1', {
-          'dependencies': [
-            '../ozone/ozone.gyp:ozone',
-          ],
-        }],
       ],
     },
     {
       'target_name': 'aura_test_support',
       'type': 'static_library',
       'dependencies': [
         '../../skia/skia.gyp:skia',
         '../../testing/gtest.gyp:gtest',
         '../compositor/compositor.gyp:compositor_test_support',
         '../events/events.gyp:events',
+        '../events/events.gyp:events_base',
         '../gfx/gfx.gyp:gfx',
         '../ui.gyp:ui',
         '../ui_unittests.gyp:ui_test_support',
         'aura',
         'aura_test_support_pak',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
@@ skipping 116 matching lines @@
       'target_name': 'aura_unittests',
       'type': 'executable',
       'dependencies': [
         '../../base/base.gyp:test_support_base',
         '../../chrome/chrome_resources.gyp:packed_resources',
         '../../skia/skia.gyp:skia',
         '../../testing/gtest.gyp:gtest',
         '../compositor/compositor.gyp:compositor_test_support',
         '../compositor/compositor.gyp:compositor',
         '../events/events.gyp:events',
+        '../events/events.gyp:events_base',
         '../gfx/gfx.gyp:gfx',
         '../gl/gl.gyp:gl',
         '../ui.gyp:ui',
         '../ui.gyp:ui_resources',
         '../ui_unittests.gyp:ui_test_support',
         'aura_test_support',
         'aura',
       ],
       'include_dirs': [
         '..',
@@ skipping 16 matching lines @@
         ['OS=="linux" and linux_use_tcmalloc==1', {
           'dependencies': [
            # See http://crbug.com/162998#c4 for why this is needed.
             '../../base/allocator/allocator.gyp:allocator',
           ],
         }],
       ],
     },
   ],
 }