Add a lock to the managed user settings page and require authentication for unlocking.

chrome/chrome_tests.gypi

Index: chrome/chrome_tests.gypi
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 19152f8710c2c7bb178fa323005762876ba6c3e8..15961722bd8b5003ae637af1955be01e633f602c 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -1336,6 +1336,10 @@
         'browser/ui/webui/options/font_settings_browsertest.js',
         'browser/ui/webui/options/language_options_browsertest.js',
         'browser/ui/webui/options/language_options_dictionary_download_browsertest.js',
+        'browser/ui/webui/options/managed_user_passphrase_handler_browsertest.cc',
+        'browser/ui/webui/options/managed_user_set_passphrase_browsertest.js',
+        'browser/ui/webui/options/managed_user_set_passphrase_test.cc',
+        'browser/ui/webui/options/managed_user_set_passphrase_test.h',
         'browser/ui/webui/options/options_browsertest.js',
         'browser/ui/webui/options/options_ui_browsertest.cc',
         'browser/ui/webui/options/options_ui_browsertest.h',