Implement a site engagement score based on time-on-site.

chrome/chrome_tests.gypi

 # 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.
 {
   'variables': {
     'chrome_browser_extensions_test_support_sources': [
       # A list of sources which is shared between different browser tests.
       'browser/apps/app_browsertest_util.cc',
       'browser/apps/app_browsertest_util.h',
       'browser/extensions/browsertest_util.cc',
@@ skipping 92 matching lines @@
       'browser/devtools/devtools_window_testing.cc',
       'browser/devtools/devtools_window_testing.h',
       'browser/do_not_track_browsertest.cc',
       'browser/dom_distiller/dom_distiller_viewer_source_browsertest.cc',
       'browser/dom_distiller/tab_utils_browsertest.cc',
       'browser/download/download_browsertest.cc',
       'browser/download/download_browsertest.h',
       'browser/download/download_danger_prompt_browsertest.cc',
       'browser/download/download_started_animation_browsertest.cc',
       'browser/download/save_page_browsertest.cc',
+      'browser/engagement/site_engagement_service_browsertest.cc',
       'browser/errorpage_browsertest.cc',
       'browser/extensions/active_script_controller_browsertest.cc',
       'browser/extensions/active_tab_apitest.cc',
       'browser/extensions/activity_log/activity_log_browsertest.cc',
       'browser/extensions/alert_apitest.cc',
       'browser/extensions/all_urls_apitest.cc',
       'browser/extensions/api/activity_log_private/activity_log_private_apitest.cc',
       'browser/extensions/api/autofill_private/autofill_private_apitest.cc',
       'browser/extensions/api/automation/automation_apitest.cc',
       'browser/extensions/api/autotest_private/autotest_private_apitest.cc',
@@ skipping 3245 matching lines @@
             'utility',
           ],
           'sources': [
             'tools/service_discovery_sniffer/service_discovery_sniffer.cc',
             'tools/service_discovery_sniffer/service_discovery_sniffer.h',
           ],
         }]
     }],
   ],  # 'conditions'
 }