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

chrome/browser/managed_mode/managed_mode.cc

 // Copyright (c) 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.
 
 #include "chrome/browser/managed_mode/managed_mode.h"
 
 #include "base/command_line.h"
 #include "base/prefs/public/pref_change_registrar.h"
 #include "base/sequenced_task_runner.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 73 matching lines @@
 // static
 void ManagedMode::RegisterPrefs(PrefServiceSimple* prefs) {
   prefs->RegisterBooleanPref(prefs::kInManagedMode, false);
 }
 
 // static
 void ManagedMode::RegisterUserPrefs(PrefServiceSyncable* prefs) {
   prefs->RegisterIntegerPref(prefs::kDefaultManagedModeFilteringBehavior,
                              2,
                              PrefServiceSyncable::UNSYNCABLE_PREF);
+  prefs->RegisterStringPref(prefs::kManagedModeLocalPassphrase,
+                            "default",

[Bernhard Bauer, 2013/01/07 14:20:22]

I think an empty string would be better as a default value (a human-readable
string would make me think it's the clear text passphrase, but it's the hash,
right?).

[Pam (message me for reviews), 2013/01/07 14:51:49]

I think we should make this empty as a default, and if the passphrase is empty,
then we don't show a dialog asking for one. That lets custodians choose not to
lock the settings if they prefer.

The first part of that can be done here; the second part (skipping the dialogs
when there's no passphrase) can be done in a later change.

+                            PrefServiceSyncable::UNSYNCABLE_PREF);
 }
 
 // static
 void ManagedMode::Init(Profile* profile) {
   GetInstance()->InitImpl(profile);
 }
 
 void ManagedMode::InitImpl(Profile* profile) {
   DCHECK(g_browser_process);
   DCHECK(g_browser_process->local_state());
@@ skipping 305 matching lines @@
   ManagedModeURLFilter::FilteringBehavior behavior =
       ManagedModeURLFilter::BehaviorFromInt(behavior_value);
   io_url_filter_context_->SetDefaultFilteringBehavior(behavior);
   ui_url_filter_context_->SetDefaultFilteringBehavior(behavior);
 }
 
 void ManagedMode::UpdateWhitelist() {
   io_url_filter_context_->LoadWhitelists(GetActiveSiteLists());
   ui_url_filter_context_->LoadWhitelists(GetActiveSiteLists());
 }