Add some unittests for EasyUnlockScreenlockStateHandler

TEST=none
BUG=none

Review URL: https://codereview.chromium.org/521713002

Cr-Commit-Position: refs/heads/master@{#292742}

chrome/chrome_tests_unit.gypi

@@ -1256,6 +1256,7 @@
         'browser/shell_integration_win_unittest.cc',
         'browser/signin/account_reconcilor_unittest.cc',
         'browser/signin/account_service_flag_fetcher_unittest.cc',
+        'browser/signin/easy_unlock_screenlock_state_handler_unittest.cc',
         'browser/signin/local_auth_unittest.cc',
         'browser/signin/signin_error_notifier_ash_unittest.cc',
         'browser/signin/signin_global_error_unittest.cc',
@@ -2106,6 +2107,7 @@
             'browser/extensions/webstore_installer_unittest.cc',
             'browser/metrics/extensions_metrics_provider_unittest.cc',
             'browser/search/hotword_service_unittest.cc',
+            'browser/signin/easy_unlock_screenlock_state_handler_unittest.cc',
             'browser/web_applications/web_app_unittest.cc',
             'common/extensions/sync_type_unittest.cc',
             'common/extensions/permissions/permission_set_unittest.cc',