Extract a Connector interface from Shell that can be cloned & passed to other threads

content/browser/frame_host/frame_mojo_shell.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 CONTENT_BROWSER_FRAME_HOST_FRAME_MOJO_SHELL_H_
 #define CONTENT_BROWSER_FRAME_HOST_FRAME_MOJO_SHELL_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
 #include "mojo/shell/public/interfaces/shell.mojom.h"
 
 namespace content {
 
 class RenderFrameHost;
 class ServiceRegistryImpl;
 
 // This provides the |mojo::shell::mojom::Shell| service interface to each
 // frame's ServiceRegistry, giving frames the ability to connect to Mojo
 // applications.
-class FrameMojoShell : public mojo::shell::mojom::Shell {
+class FrameMojoShell : public mojo::shell::mojom::Shell,
+                       public mojo::shell::mojom::Connector {
  public:
   explicit FrameMojoShell(RenderFrameHost* frame_host);
   ~FrameMojoShell() override;
 
   void BindRequest(
       mojo::InterfaceRequest<mojo::shell::mojom::Shell> shell_request);
 
  private:
   // mojo::Shell:
+  void GetConnector(mojo::shell::mojom::ConnectorRequest request) override;
+  void QuitApplication() override;
+
+  // mojo::Connector:
   void Connect(
       const mojo::String& application_url,
       uint32_t user_id,
       mojo::shell::mojom::InterfaceProviderRequest services,
       mojo::shell::mojom::InterfaceProviderPtr exposed_services,
       mojo::shell::mojom::CapabilityFilterPtr filter,
-      const ConnectCallback& callback) override;
-  void QuitApplication() override;
+      const mojo::shell::mojom::Connector::ConnectCallback& callback) override;
+  void Clone(mojo::shell::mojom::ConnectorRequest request) override;
 
   ServiceRegistryImpl* GetServiceRegistry();
 
   RenderFrameHost* frame_host_;
   mojo::BindingSet<mojo::shell::mojom::Shell> bindings_;
+  mojo::BindingSet<mojo::shell::mojom::Connector> connectors_;
 
   // ServiceRegistry providing browser services to connected applications.
   scoped_ptr<ServiceRegistryImpl> service_registry_;
   mojo::BindingSet<mojo::shell::mojom::InterfaceProvider>
       service_provider_bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameMojoShell);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_MOJO_SHELL_H_