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

mojo/shell/native_runner_delegate.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 MOJO_SHELL_NATIVE_RUNNER_DELEGATE_H_
 #define MOJO_SHELL_NATIVE_RUNNER_DELEGATE_H_
 
 namespace base {
 class CommandLine;
 }
 
 namespace mojo {
+class Identity;
 namespace shell {
 
-class Identity;
-
 class NativeRunnerDelegate {
  public:
   // Called to adjust the commandline for launching the specified app.
   // WARNING: this is called on a background thread.
   virtual void AdjustCommandLineArgumentsForTarget(
       const Identity& target,
       base::CommandLine* command_line) = 0;
 
  protected:
   virtual ~NativeRunnerDelegate() {}
 };
 
 }  // namespace shell
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_NATIVE_RUNNER_DELEGATE_H_