Add a instance groups to Connect(), and introduce an Identity struct.

mojo/shell/native_runner.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 MOJO_SHELL_NATIVE_RUNNER_H_
 #define MOJO_SHELL_NATIVE_RUNNER_H_
 
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/process/process_handle.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
 #include "mojo/shell/public/interfaces/shell_client.mojom.h"
 #include "mojo/shell/public/interfaces/shell_client_factory.mojom.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace mojo {
+class Identity;
 namespace shell {
 
-class Identity;
 
 // Shell requires implementations of NativeRunner and NativeRunnerFactory to run
 // native applications.
 class NativeRunner {
  public:
   virtual ~NativeRunner() {}
 
   // Loads the app in the file at |app_path| and runs it on some other
   // thread/process.
   virtual void Start(
       const base::FilePath& app_path,
       const Identity& target,
       bool start_sandboxed,
       InterfaceRequest<mojom::ShellClient> request,
       const base::Callback<void(base::ProcessId)>& pid_available_callback,
       const base::Closure& app_completed_callback) = 0;
 };
 
 class NativeRunnerFactory {
  public:
   virtual ~NativeRunnerFactory() {}
   virtual scoped_ptr<NativeRunner> Create(const base::FilePath& app_path) = 0;
 };
 
 }  // namespace shell
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_NATIVE_RUNNER_H_