Add a set passphrase dialog for managed user accounts.

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 28db251e1c510406937cea3628787b420e5bd77d..af64f3acad5068c0ae12e22acbd1e6519f6b78e9 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -35,6 +35,13 @@ const char kManagedModeManualHosts[] = "profile.managed.manual_hosts";
 // Maps URLs to whether the URL is manually allowed or blocked.
 const char kManagedModeManualURLs[] = "profile.managed.manual_urls";
 
+// 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
+// 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";
+
 // 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.