Add dependency to ax_gen for content_browser_test_utils.

content/content_tests.gypi

 # Copyright (c) 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': {
     'layouttest_support_content_sources': [
       'public/test/layouttest_support.h',
       'public/test/nested_message_pump_android.cc',
       'public/test/nested_message_pump_android.h',
@@ skipping 1063 matching lines @@
             }],
           ],
         },
         {
           'target_name': 'content_browser_test_support',
           'type': 'static_library',
           'dependencies': [
             'content_shell_lib',
             '../skia/skia.gyp:skia',
             '../testing/gtest.gyp:gtest',
+            '../ui/accessibility/accessibility.gyp:ax_gen',
           ],
           'sources': [
             'test/content_test_launcher.cc',
             'public/test/content_browser_test.cc',
             'public/test/content_browser_test.h',
             'public/test/content_browser_test_utils.cc',
             'public/test/content_browser_test_utils.h',
             'public/test/content_browser_test_utils_mac.mm',
           ],
           'include_dirs': [
@@ skipping 850 matching lines @@
                   'files': ['<(PRODUCT_DIR)/libnpapi_test_plugin.so'],
                 },
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }