Trying changes to see the perfomance impact on Mac....

chrome/chrome_tests.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.
 
 {
   'variables' : {
     'pyautolib_sources': [
       'app/chrome_command_ids.h',
       'app/chrome_dll_resource.h',
       'common/automation_constants.h',
@@ skipping 1349 matching lines @@
         'browser/importer/safari_importer_unittest.mm',
         'browser/importer/toolbar_importer_unittest.cc',
         'browser/instant/instant_loader_manager_unittest.cc',
         'browser/instant/promo_counter_unittest.cc',
         'browser/keychain_mock_mac.cc',
         'browser/keychain_mock_mac.h',
         'browser/mach_broker_mac_unittest.cc',
         'browser/metrics/metrics_log_unittest.cc',
         'browser/metrics/metrics_response_unittest.cc',
         'browser/metrics/metrics_service_unittest.cc',
+        'browser/metrics/thread_watcher_unittest.cc',
         'browser/mock_plugin_exceptions_table_model.cc',
         'browser/mock_plugin_exceptions_table_model.h',
         'browser/net/connection_tester_unittest.cc',
         'browser/net/gaia/token_service_unittest.cc',
         'browser/net/gaia/token_service_unittest.h',
         'browser/net/chrome_net_log_unittest.cc',
         'browser/net/load_timing_observer_unittest.cc',
         'browser/net/passive_log_collector_unittest.cc',
         'browser/net/predictor_unittest.cc',
         'browser/net/pref_proxy_config_service_unittest.cc',
@@ skipping 2408 matching lines @@
       ]
     }],  # 'coverage!=0'
   ],  # 'conditions'
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: