Reify view ownership as a message pipe.

services/ui/view_manager/view_host_impl.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 SERVICES_UI_VIEW_MANAGER_VIEW_HOST_IMPL_H_
 #define SERVICES_UI_VIEW_MANAGER_VIEW_HOST_IMPL_H_
 
 #include "base/macros.h"
 #include "mojo/common/binding_set.h"
-#include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/services/ui/views/interfaces/views.mojom.h"
-#include "services/ui/view_manager/view_registry.h"
-#include "services/ui/view_manager/view_state.h"
 
 namespace view_manager {
 
+class ViewRegistry;
+class ViewState;
+
 // ViewHost interface implementation.
 // This object is owned by its associated ViewState.
-class ViewHostImpl : public mojo::ui::ViewHost, public mojo::ServiceProvider {
+class ViewHostImpl : public mojo::ui::ViewHost,
+                     public mojo::ui::ViewOwner,
+                     public mojo::ServiceProvider {
  public:
-  ViewHostImpl(ViewRegistry* registry,
-               ViewState* state,
-               mojo::InterfaceRequest<mojo::ui::ViewHost> view_host_request);
+  ViewHostImpl(ViewRegistry* registry, ViewState* state);
   ~ViewHostImpl() override;
 
-  void set_view_host_connection_error_handler(const base::Closure& handler) {
-    binding_.set_connection_error_handler(handler);
-  }
-
  private:
   // |ViewHost|:
+  void GetToken(const mojo::ui::ViewHost::GetTokenCallback& callback) override;
   void GetServiceProvider(mojo::InterfaceRequest<mojo::ServiceProvider>
                               service_provider_request) override;
   void CreateScene(
       mojo::InterfaceRequest<mojo::gfx::composition::Scene> scene) override;
   void RequestLayout() override;
   void AddChild(uint32_t child_key,
-                mojo::ui::ViewTokenPtr child_view_token) override;
-  void RemoveChild(uint32_t child_key) override;
+                mojo::ui::ViewOwnerPtr child_view_owner) override;
+  void RemoveChild(uint32_t child_key,
+                   mojo::InterfaceRequest<mojo::ui::ViewOwner>
+                       transferred_view_owner_request) override;
   void LayoutChild(uint32_t child_key,
                    mojo::ui::ViewLayoutParamsPtr child_layout_params,
                    const LayoutChildCallback& callback) override;
 
   // |ServiceProvider|:
   void ConnectToService(const mojo::String& service_name,
                         mojo::ScopedMessagePipeHandle client_handle) override;
 
   ViewRegistry* const registry_;
   ViewState* const state_;
-  mojo::Binding<mojo::ui::ViewHost> binding_;
   mojo::BindingSet<mojo::ServiceProvider> service_provider_bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(ViewHostImpl);
 };
 
 }  // namespace view_manager
 
 #endif  // SERVICES_UI_VIEW_MANAGER_VIEW_HOST_IMPL_H_