Use mojo SystemTray interfaces for both mash and classic ash

ash/shell/shell_delegate_impl.cc

 // Copyright (c) 2012 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 "ash/shell/shell_delegate_impl.h"
 
 #include "ash/app_list/app_list_presenter_delegate_factory.h"
 #include "ash/common/accessibility_delegate.h"
 #include "ash/common/default_accessibility_delegate.h"
 #include "ash/common/gpu_support_stub.h"
@@ skipping 178 matching lines @@
 
 }  // namespace
 
 ShellDelegateImpl::ShellDelegateImpl()
     : shelf_delegate_(nullptr),
       app_list_presenter_delegate_factory_(new AppListPresenterDelegateFactory(
           base::WrapUnique(new AppListViewDelegateFactoryImpl))) {}
 
 ShellDelegateImpl::~ShellDelegateImpl() {}
 
+::shell::Connector* ShellDelegateImpl::GetShellConnector() const {
+  return nullptr;
+}
+
 bool ShellDelegateImpl::IsFirstRunAfterBoot() const {
   return false;
 }
 
 bool ShellDelegateImpl::IsIncognitoAllowed() const {
   return true;
 }
 
 bool ShellDelegateImpl::IsMultiProfilesEnabled() const {
   return false;
@@ skipping 80 matching lines @@
 base::string16 ShellDelegateImpl::GetProductName() const {
   return base::string16();
 }
 
 gfx::Image ShellDelegateImpl::GetDeprecatedAcceleratorImage() const {
   return gfx::Image();
 }
 
 }  // namespace shell
 }  // namespace ash