Add SafeBrowsingNavigationObserver to listen to navigation events

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.
 {
   'variables': {
     'chrome_unit_tests_sources': [
       # 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',
@@ skipping 803 matching lines @@
       'browser/safe_browsing/incident_reporting/suspicious_module_incident_unittest.cc',
       'browser/safe_browsing/incident_reporting/tracked_preference_incident_unittest.cc',
       'browser/safe_browsing/incident_reporting/variations_seed_signature_incident_unittest.cc',
       'browser/safe_browsing/local_database_manager_unittest.cc',
       'browser/safe_browsing/local_two_phase_testserver.cc',
       'browser/safe_browsing/path_sanitizer_unittest.cc',
       'browser/safe_browsing/permission_reporter_unittest.cc',
       'browser/safe_browsing/protocol_manager_unittest.cc',
       'browser/safe_browsing/protocol_parser_unittest.cc',
       'browser/safe_browsing/safe_browsing_database_unittest.cc',
+      'browser/safe_browsing/safe_browsing_navigation_observer_unittest.cc',
       'browser/safe_browsing/safe_browsing_store_file_unittest.cc',
       'browser/safe_browsing/safe_browsing_store_unittest.cc',
       'browser/safe_browsing/sandboxed_dmg_analyzer_mac_unittest.cc',
       'browser/safe_browsing/sandboxed_zip_analyzer_unittest.cc',
       'browser/safe_browsing/signature_evaluator_mac_unittest.cc',
       'browser/safe_browsing/two_phase_uploader_unittest.cc',
       'common/safe_browsing/binary_feature_extractor_mac_unittest.cc',
       'common/safe_browsing/binary_feature_extractor_unittest.cc',
       'common/safe_browsing/binary_feature_extractor_win_unittest.cc',
       'common/safe_browsing/download_protection_util_unittest.cc',
@@ skipping 2181 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }