Simplify the user agent overriding code, in preparation for moving it out of src/webkit.

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.
 
 {
   'targets': [
     {
       'target_name': 'test_support_content',
       'type': 'static_library',
       'dependencies': [
@@ skipping 616 matching lines @@
         '../webkit/browser/fileapi/sandbox_origin_database_unittest.cc',
         '../webkit/browser/fileapi/sandbox_prioritized_origin_database_unittest.cc',
         '../webkit/browser/fileapi/timed_task_helper_unittest.cc',
         '../webkit/child/multipart_response_delegate_unittest.cc',
         '../webkit/child/touch_fling_gesture_curve_unittest.cc',
         '../webkit/common/blob/shareable_file_reference_unittest.cc',
         '../webkit/common/cursors/webcursor_unittest.cc',
         '../webkit/common/database/database_connections_unittest.cc',
         '../webkit/common/database/database_identifier_unittest.cc',
         '../webkit/common/fileapi/file_system_util_unittest.cc',
-        '../webkit/common/user_agent/user_agent_unittest.cc',
         '../webkit/browser/quota/mock_quota_manager.cc',
         '../webkit/browser/quota/mock_quota_manager.h',
         '../webkit/browser/quota/mock_quota_manager_proxy.cc',
         '../webkit/browser/quota/mock_quota_manager_proxy.h',
         '../webkit/browser/quota/mock_quota_manager_unittest.cc',
         '../webkit/browser/quota/mock_special_storage_policy.cc',
         '../webkit/browser/quota/mock_special_storage_policy.h',
         '../webkit/browser/quota/mock_storage_client.cc',
         '../webkit/browser/quota/mock_storage_client.h',
         '../webkit/browser/quota/quota_database_unittest.cc',
@@ skipping 1057 matching lines @@
                   'files': ['<(PRODUCT_DIR)/libnpapi_test_plugin.so'],
                 },
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }