[Reland] cheets: implement cros side of WallpaperManager API.

components/arc/arc_bridge_host_impl.h

 // 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.
 
 #ifndef COMPONENTS_ARC_ARC_BRIDGE_HOST_IMPL_H_
 #define COMPONENTS_ARC_ARC_BRIDGE_HOST_IMPL_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 47 matching lines @@
   void OnObbMounterInstanceReady(
       mojom::ObbMounterInstancePtr obb_mounter_ptr) override;
   void OnPolicyInstanceReady(mojom::PolicyInstancePtr policy_ptr) override;
   void OnPowerInstanceReady(mojom::PowerInstancePtr power_ptr) override;
   void OnPrintInstanceReady(mojom::PrintInstancePtr print_ptr) override;
   void OnProcessInstanceReady(mojom::ProcessInstancePtr process_ptr) override;
   void OnStorageManagerInstanceReady(
       mojom::StorageManagerInstancePtr storage_manager_ptr) override;
   void OnTtsInstanceReady(mojom::TtsInstancePtr tts_ptr) override;
   void OnVideoInstanceReady(mojom::VideoInstancePtr video_ptr) override;
+  void OnWallpaperInstanceReady(
+      mojom::WallpaperInstancePtr wallpaper_ptr) override;
 
  private:
   // Called when the bridge channel is closed. This typically only happens when
   // the ARC instance crashes.
   void OnClosed();
 
   // The common implementation to handle ArcBridgeHost overrides.
   // |T| is a ARC Mojo Instance type.
   template <typename T>
   void OnInstanceReady(InstanceHolder<T>* holder, mojo::InterfacePtr<T> ptr);
 
   // Called if one of the established channels is closed.
   void OnChannelClosed(MojoChannel* channel);
 
   base::ThreadChecker thread_checker_;
 
   mojo::Binding<mojom::ArcBridgeHost> binding_;
   mojom::ArcBridgeInstancePtr instance_;
 
   // Put as a last member to ensure that any callback tied to the elements
   // is not invoked.
   std::vector<std::unique_ptr<MojoChannel>> mojo_channels_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcBridgeHostImpl);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_ARC_BRIDGE_HOST_IMPL_H_