Convert utility process extension ParseUpdate IPC to mojo

extensions/test/test_content_utility_client.cc

 // Copyright 2015 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 "extensions/test/test_content_utility_client.h"
 
 namespace extensions {
 
 TestContentUtilityClient::TestContentUtilityClient() = default;
 
 TestContentUtilityClient::~TestContentUtilityClient() = default;
 
 void TestContentUtilityClient::UtilityThreadStarted() {
-  UtilityHandler::UtilityThreadStarted();
+  utility_handler::UtilityThreadStarted();
 }
 
 void TestContentUtilityClient::ExposeInterfacesToBrowser(
     service_manager::InterfaceRegistry* registry) {
-  UtilityHandler::ExposeInterfacesToBrowser(registry, false);
-}
-
-bool TestContentUtilityClient::OnMessageReceived(const IPC::Message& message) {
-  return utility_handler_.OnMessageReceived(message);
+  utility_handler::ExposeInterfacesToBrowser(registry, false);
 }
 
 }  // namespace extensions