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

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 0f4feaff7ebbf7115314c12748d56d57cf9a24c9..40cf59070e20a74253b6c45cb8604def90be357c 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -38,6 +38,14 @@ const char kManagedModeWhitelist[] = "profile.managed.whitelist";
 // List of pages that are manually blocked.
 const char kManagedModeBlacklist[] = "profile.managed.blacklist";
 
+// This preference is used to store the hash of a password of the custodian of
+// a managed user. It allows to unlock options which should be not available to

[Pam (message me for reviews), 2013/01/28 13:53:27]

This use of "unlock" makes it sound like it's the opposite of the "locked" pref
below.

[Adrian Kuegel, 2013/01/28 15:41:44]

As I removed the "locked" pref, I guess it is now ok.

+// the managed user. The salt preference is used to derive the hash from the
+// password.
+const char kManagedModeLocalPassphrase[] = "managed_mode.passphrase";
+const char kManagedModeLocalSalt[] = "managed_mode.salt";
+const char kManagedModeLocked[] = "managed_mode.locked";
+
 // Used to determine if the last session exited cleanly. Set to false when
 // first opened, and to true when closing. On startup if the value is false,
 // it means the profile didn't exit cleanly.