Simplify the user agent code some more since after r255534 it's not affected by the site's URL.

webkit/common/user_agent/webkit_user_agent.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.
 
 {
   'targets': [
     {
       'target_name': 'user_agent',
       'type': '<(component)',
       'defines': [
         'WEBKIT_USER_AGENT_IMPLEMENTATION',
       ],
       'variables': {
         'chromium_code': 1,
       },
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/base/base.gyp:base_i18n',
         '<(DEPTH)/url/url.gyp:url_lib',
       ],
       'sources': [
-        'user_agent.cc',
-        'user_agent.h',
         'user_agent_util.cc',
         'user_agent_util_ios.mm',
         'user_agent_util.h',
         'webkit_user_agent_export.h',
       ],
       'conditions': [
         ['OS == "ios"', {
           # iOS has different user-agent construction utilities, since the
           # version strings is not derived from webkit_version, and follows
           # a different format.
@@ skipping 45 matching lines @@
             ],
           },
           # Dependents may rely on files generated by this target or one of its
           # own hard dependencies.
           'hard_dependency': 1,
         },
       ],
     }],
   ],
 }