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

mojo/shell/public/cpp/connector.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_PUBLIC_CPP_CONNECTOR_H_
 #define MOJO_SHELL_PUBLIC_CPP_CONNECTOR_H_
 
 #include "mojo/shell/public/cpp/connection.h"
+#include "mojo/shell/public/cpp/identity.h"
 #include "mojo/shell/public/interfaces/connector.mojom.h"
 
 namespace mojo {
 
 // An interface that encapsulates the Mojo Shell's broker interface by which
 // connections between applications are established. Once Connect() is called,
 // this class is bound to the thread the call was made on and it cannot be
 // passed to another thread without calling Clone().
 // An instance of this class is created internally by ShellConnection for use
 // on the thread ShellConnection is instantiated on, and this interface is
 // wrapped by the Shell interface.
 // To use this interface on other threads, call Shell::CloneConnector() and
 // pass the result to another thread. To pass to subsequent threads, call
 // Clone() on instances of this object.
 // While instances of this object are owned by the caller, the underlying
 // connection with the shell is bound to the lifetime of the instance that
 // created it, i.e. when the application is terminated the Connector pipe is
 // closed.
 class Connector {
  public:
   virtual ~Connector() {}
 
   class ConnectParams {
    public:
+    explicit ConnectParams(const Identity& target);
     explicit ConnectParams(const std::string& name);
     ~ConnectParams();
 
-    const std::string& name() { return name_; }
-    void set_user_id(const std::string& user_id) { user_id_ = user_id; }
-    const std::string& user_id() const { return user_id_; }
+    const Identity& target() { return target_; }
+    void set_target(const Identity& target) { target_ = target; }
 
    private:
-    std::string name_;
-    std::string user_id_;
+    Identity target_;
 
     DISALLOW_COPY_AND_ASSIGN(ConnectParams);
   };
 
   // Requests a new connection to an application. Returns a pointer to the
   // connection if the connection is permitted by this application's delegate,
   // or nullptr otherwise. Caller takes ownership.
   // Once this method is called, this object is bound to the thread on which the
   // call took place. To pass to another thread, call Clone() and pass the
   // result.
@@ skipping 17 matching lines @@
 
   // Creates a new instance of this class which may be passed to another thread.
   // The returned object may be passed multiple times until Connect() is called,
   // at which point this method must be called again to pass again.
   virtual scoped_ptr<Connector> Clone() = 0;
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_PUBLIC_CPP_CONNECTOR_H_