Dead code removal: remove MetricsResponse implementation and tests

chrome/chrome_tests.gypi

 # Copyright (c) 2012 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' : {
     'pyautolib_sources': [
       'app/chrome_command_ids.h',
       'app/chrome_dll_resource.h',
       'common/automation_constants.h',
       'common/pref_names.cc',
@@ skipping 1328 matching lines @@
         'browser/mac/keystone_glue_unittest.mm',
         'browser/managed_mode_unittest.cc',
         'browser/media/media_internals_unittest.cc',
         'browser/media_gallery/media_device_notifications_chromeos_unittest.cc',
         'browser/media_gallery/media_device_notifications_linux_unittest.cc',
         'browser/media_gallery/media_device_notifications_utils_unittest.cc',
         'browser/media_gallery/media_device_notifications_window_win_unittest.cc',
         'browser/media_gallery/media_gallery_database_unittest.cc',
         'browser/metrics/metrics_log_unittest.cc',
         'browser/metrics/metrics_log_serializer_unittest.cc',
-        'browser/metrics/metrics_response_unittest.cc',
         'browser/metrics/metrics_service_unittest.cc',
         'browser/metrics/thread_watcher_unittest.cc',
         'browser/metrics/variations_service_unittest.cc',
         'browser/nacl_host/nacl_validation_cache_unittest.cc',
         'browser/nacl_host/pnacl_file_host_unittest.cc',
         'browser/net/chrome_fraudulent_certificate_reporter_unittest.cc',
         'browser/net/chrome_net_log_unittest.cc',
         'browser/net/clear_on_exit_policy_unittest.cc',
         'browser/net/connection_tester_unittest.cc',
         'browser/net/gaia/gaia_oauth_fetcher_unittest.cc',
@@ skipping 3266 matching lines @@
             'input_jars_paths': [
               '<(PRODUCT_DIR)/lib.java/chromium_base.jar',
              ],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],  # 'conditions'
 }