Setup DiscardableMemory in the ash process

ash/mus/window_manager_application.h

 // 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.
 
 #ifndef ASH_MUS_WINDOW_MANAGER_APPLICATION_H_
 #define ASH_MUS_WINDOW_MANAGER_APPLICATION_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <set>
 
 #include "ash/public/interfaces/wallpaper.mojom.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "services/service_manager/public/cpp/service.h"
 #include "services/tracing/public/cpp/provider.h"
 #include "services/ui/common/types.h"
 
 namespace aura {
 class WindowTreeClient;
 }
 
 namespace base {
 class SequencedWorkerPool;
+class Thread;
 }
 
 namespace chromeos {
 namespace system {
 class ScopedFakeStatisticsProvider;
 }
 }
 
+namespace discardable_memory {
+class ClientDiscardableSharedMemoryManager;
+}
+
 namespace views {
 class AuraInit;
 }
 
 namespace ash {
 namespace test {
 class AshTestHelper;
 }
 namespace mus {
 
@@ skipping 21 matching lines @@
   void InitializeComponents();
   void ShutdownComponents();
 
   // service_manager::Service:
   void OnStart() override;
   bool OnConnect(const service_manager::ServiceInfo& remote_info,
                  service_manager::InterfaceRegistry* registry) override;
 
   tracing::Provider tracing_;
 
+  std::unique_ptr<base::Thread> io_thread_;
+
   std::unique_ptr<views::AuraInit> aura_init_;
 
   std::unique_ptr<WindowManager> window_manager_;
 
   // A blocking pool used by the WindowManager's shell; not used in tests.
   scoped_refptr<base::SequencedWorkerPool> blocking_pool_;
 
   std::unique_ptr<NetworkConnectDelegateMus> network_connect_delegate_;
   std::unique_ptr<chromeos::system::ScopedFakeStatisticsProvider>
       statistics_provider_;
+  std::unique_ptr<discardable_memory::ClientDiscardableSharedMemoryManager>
+      discardable_shared_memory_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowManagerApplication);
 };
 
 }  // namespace mus
 }  // namespace ash
 
 #endif  // ASH_MUS_WINDOW_MANAGER_APPLICATION_H_