ChromeOS: Add RenameCryptohome and migration code.

chromeos/cryptohome/homedir_methods.cc

Index: chromeos/cryptohome/homedir_methods.cc
diff --git a/chromeos/cryptohome/homedir_methods.cc b/chromeos/cryptohome/homedir_methods.cc
index 81bf15349dc9dcbf8269be9aba8cd971b053b34f..bd276eceeb5206066aed18322303f6299baa117d 100644
--- a/chromeos/cryptohome/homedir_methods.cc
+++ b/chromeos/cryptohome/homedir_methods.cc
@@ -278,6 +278,14 @@ class HomedirMethodsImpl : public HomedirMethods {
                    weak_ptr_factory_.GetWeakPtr(), callback));
   }
 
+  void RenameCryptohome(const Identification& id_from,
+                        const Identification& id_to,
+                        const Callback& callback) override {
+    DBusThreadManager::Get()->GetCryptohomeClient()->RenameCryptohome(
+        id_from, id_to, base::Bind(&HomedirMethodsImpl::OnBaseReplyCallback,
+                                   weak_ptr_factory_.GetWeakPtr(), callback));
+  }
+
  private:
   void OnGetKeyDataExCallback(const GetKeyDataCallback& callback,
                               chromeos::DBusMethodCallStatus call_status,