First step to move common accessibility code out of content.

ui/ui_unittests.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 127 matching lines @@
         'gfx/shadow_value_unittest.cc',
         'gfx/size_unittest.cc',
         'gfx/skbitmap_operations_unittest.cc',
         'gfx/text_elider_unittest.cc',
         'gfx/text_utils_unittest.cc',
         'gfx/vector2d_unittest.cc',
         'gfx/vector3d_unittest.cc',
       ],
       'all_sources': [
         '<@(_common_sources)',
+        'accessibility/ax_tree_unittest.cc',
         'base/accelerators/accelerator_manager_unittest.cc',
         'base/accelerators/menu_label_accelerator_util_linux_unittest.cc',
         'base/clipboard/clipboard_unittest.cc',
         'base/clipboard/custom_data_helper_unittest.cc',
         'base/cocoa/base_view_unittest.mm',
         'base/cocoa/cocoa_event_utils_unittest.mm',
         'base/cocoa/controls/blue_label_button_unittest.mm',
         'base/cocoa/controls/hover_image_menu_button_unittest.mm',
         'base/cocoa/controls/hyperlink_button_cell_unittest.mm',
         'base/cocoa/focus_tracker_unittest.mm',
@@ skipping 231 matching lines @@
           'variables': {
             'test_suite_name': 'ui_unittests',
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)ui_unittests<(SHARED_LIB_SUFFIX)',
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }