Add a set passphrase dialog for managed user accounts.

chrome/browser/managed_mode/managed_user_service.cc

Index: chrome/browser/managed_mode/managed_user_service.cc
diff --git a/chrome/browser/managed_mode/managed_user_service.cc b/chrome/browser/managed_mode/managed_user_service.cc
index 045dc9a5c795fda56c9526589bd2ec8bf465662f..a00442956baa3ad262ab6d18f33636f62608cf08 100644
--- a/chrome/browser/managed_mode/managed_user_service.cc
+++ b/chrome/browser/managed_mode/managed_user_service.cc
@@ -107,6 +107,12 @@ void ManagedUserService::RegisterUserPrefs(PrefRegistrySyncable* registry) {
   registry->RegisterIntegerPref(prefs::kDefaultManagedModeFilteringBehavior,
                                 ManagedModeURLFilter::BLOCK,
                                 PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterStringPref(prefs::kManagedModeLocalPassphrase,
+                               "",
+                               PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterStringPref(prefs::kManagedModeLocalSalt,
+                               "",
+                               PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 scoped_refptr<const ManagedModeURLFilter>