Expose an accessible relation between the main window and active alert.

ui/views/views.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,
   },
   'target_defaults': {
     'conditions': [
       ['use_aura==1', {
@@ skipping 659 matching lines @@
           'sources!': [
             'touchui/touch_selection_controller_impl_unittest.cc',
           ],
         }, { # use_chromeos==1
           'sources/': [
             ['exclude', 'ime/input_method_bridge_unittest.cc'],
             ['exclude', 'widget/desktop_aura'],
           ],
         }],
         ['OS=="win"', {
+          'dependencies': [
+            '../../third_party/iaccessible2/iaccessible2.gyp:iaccessible2',
+          ],
           'link_settings': {
             'libraries': [
               '-limm32.lib',
               '-loleacc.lib',
               '-lcomctl32.lib',
             ]
           },
           'include_dirs': [
             '../third_party/wtl/include',
           ],
@@ skipping 23 matching lines @@
         }],
         ['use_aura==1', {
           'dependencies': [
             '../aura/aura.gyp:aura_test_support',
           ],
         }],
       ],
     },  # target_name: views_unittests
   ],
 }