Rename ApplicationDelegate to ShellClient

mojo/shell/public/cpp/lib/application_delegate.cc

-// Copyright 2014 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 "mojo/shell/public/cpp/application_delegate.h"
-
-namespace mojo {
-
-ApplicationDelegate::ApplicationDelegate() {
-}
-ApplicationDelegate::~ApplicationDelegate() {
-}
-
-void ApplicationDelegate::Initialize(Shell* app, const std::string& url,
-                                     uint32_t id) {
-}
-
-bool ApplicationDelegate::AcceptConnection(ApplicationConnection* connection) {
-  return true;
-}
-
-bool ApplicationDelegate::ShellConnectionLost() {
-  return true;
-}
-
-void ApplicationDelegate::Quit() {
-}
-
-}  // namespace mojo