cryptohome: Add dbus method and signal name for encryption migration.

chromeos/cryptohome/mock_homedir_methods.h

Index: chromeos/cryptohome/mock_homedir_methods.h
diff --git a/chromeos/cryptohome/mock_homedir_methods.h b/chromeos/cryptohome/mock_homedir_methods.h
index a8ca39470c0934ecaece2570894d58f5fea38b72..8bbcb6a3e7705a005680c0bc34684aafa14a367b 100644
--- a/chromeos/cryptohome/mock_homedir_methods.h
+++ b/chromeos/cryptohome/mock_homedir_methods.h
@@ -58,6 +58,10 @@ class CHROMEOS_EXPORT MockHomedirMethods : public HomedirMethods {
   MOCK_METHOD2(GetAccountDiskUsage,
                void(const Identification& id,
                     const GetAccountDiskUsageCallback& callback));
+  MOCK_METHOD3(MigrateToDircrypto,
+               void(const Identification& id,
+                    const Authorization& auth,
+                    const Callback& callback));
 
   void set_mount_callback(const base::Closure& callback) {
     on_mount_called_ = callback;