Use mojo Shelf interfaces for both mash and classic ash.

ash/common/mojo_interface_factory.cc

 // Copyright 2016 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/common/mojo_interface_factory.h"
 
+#include "ash/common/shelf/shelf_controller.h"
 #include "ash/common/system/tray/system_tray_controller.h"
 #include "ash/common/wm_shell.h"
 #include "base/bind.h"
 #include "services/shell/public/cpp/interface_registry.h"
 
 namespace ash {
 
 namespace {
 
+void BindShelfControllerRequestOnMainThread(
+    mojom::ShelfControllerRequest request) {
+  WmShell::Get()->shelf_controller()->BindRequest(std::move(request));
+}
+
 void BindSystemTrayRequestOnMainThread(mojom::SystemTrayRequest request) {
   WmShell::Get()->system_tray_controller()->BindRequest(std::move(request));
 }
 
 }  // namespace
 
 namespace mojo_interface_factory {
 
 void RegisterInterfaces(
     shell::InterfaceRegistry* registry,
     scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner) {
+  registry->AddInterface(base::Bind(&BindShelfControllerRequestOnMainThread),
+                         main_thread_task_runner);
   registry->AddInterface(base::Bind(&BindSystemTrayRequestOnMainThread),
                          main_thread_task_runner);
 }
 
 }  // namespace mojo_interface_factory
 
 }  // namespace ash