Reverting based on discussions on #chromium with shess and rsleevi

chrome/chrome_browser.gypi

 # Copyright (c) 2011 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': 'browser',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 1305 matching lines @@
         'browser/history/expire_history_backend.cc',
         'browser/history/expire_history_backend.h',
         'browser/history/history.cc',
         'browser/history/history.h',
         'browser/history/history_backend.cc',
         'browser/history/history_backend.h',
         'browser/history/history_database.cc',
         'browser/history/history_database.h',
         'browser/history/history_extension_api.cc',
         'browser/history/history_extension_api.h',
-        'browser/history/history_field_trial.cc',
-        'browser/history/history_field_trial.h',
         'browser/history/history_marshaling.h',
         'browser/history/history_notifications.cc',
         'browser/history/history_notifications.h',
         'browser/history/history_publisher.cc',
         'browser/history/history_publisher.h',
         'browser/history/history_publisher_none.cc',
         'browser/history/history_publisher_win.cc',
         'browser/history/history_tab_helper.cc',
         'browser/history/history_tab_helper.h',
         'browser/history/history_types.cc',
@@ skipping 3915 matching lines @@
       'type': 'static_library',
       'sources': [ 'browser/history/in_memory_url_index_cache.proto' ],
       'variables': {
         'proto_in_dir': 'browser/history',
         'proto_out_dir': 'chrome/browser/history',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }