Collect UMA statistics on which chrome://flags lead to chrome restart on ChromeOS.

chrome/chrome_tests_unit.gypi

 # Copyright 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.
 {
   'targets': [
     {
       # This target contains mocks and test utilities that don't belong in
       # production libraries but are used by more than one test executable.
       'target_name': 'test_support_common',
       'type': 'static_library',
@@ skipping 542 matching lines @@
         '../extensions/common/manifest_handlers/externally_connectable_unittest.cc',
         '../extensions/common/manifest_handlers/file_handler_manifest_unittest.cc',
         '../extensions/common/manifest_handlers/shared_module_manifest_unittest.cc',
         '../extensions/common/message_bundle_unittest.cc',
         '../extensions/common/permissions/api_permission_set_unittest.cc',
         '../extensions/common/permissions/permissions_data_unittest.cc',
         '../extensions/common/url_pattern_set_unittest.cc',
         '../extensions/common/url_pattern_unittest.cc',
         '../extensions/renderer/activity_log_converter_strategy_unittest.cc',
         '../extensions/renderer/script_context_set_unittest.cc',
+        # histograms.xml is analyzed by AboutFlagsHistogramTest, so this
+        # dependency is needed to make commit bots run unit_tests on
+        # histograms.xml changes.
+        '../tools/metrics/histograms/histograms.xml',
         'app/chrome_dll.rc',
         # All unittests in browser, common, renderer and service.
         'browser/about_flags_unittest.cc',
         'browser/android/bookmarks/partner_bookmarks_shim_unittest.cc',
         'browser/android/thumbnail/scoped_ptr_expiring_cache_unittest.cc',
         # mock_google_location_settings_helper could logically go in
         # test_support_unit. However tests suites in the internal repository
         # depend on an alternate implementation so instead each test suite
         # includes the relevant version directly.
         'browser/android/mock_google_location_settings_helper.cc',
@@ skipping 2321 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }