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

mojo/shell/public/interfaces/shell.mojom

 // 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.
 
 module mojo.shell.mojom;
 
 import "mojo/shell/public/interfaces/connector.mojom";
 import "mojo/shell/public/interfaces/shell_client_factory.mojom";
 
 struct InstanceInfo {
   uint32 id;
-  string name;
-  string qualifier;
+  Identity identity;
   uint32 pid;
 };
 
 // Implemented by a client that wishes to be informed when the list of running
 // instances changes.
 interface InstanceListener {
   // Called once when the listener is added via Shell::AddInstanceListener() to
   // provide the initial list of instances that the listener observes changes
   // against.
   SetExistingInstances(array<InstanceInfo> instances);
@@ skipping 36 matching lines @@
 
 interface Shell {
   // Instructs the Shell to create an instance for an existing process at the
   // other end of |factory|, and perform applicable initialization. |user_id| is
   // the user the instance should be created as. This is typically set to
   // Connector::kUserInherit, unless the application has the ability to connect
   // as other users. |result| passed in the response indicates (via a MojoResult
   // code, see connector.mojom for definitions) the status of the instance
   // creation.
   CreateInstance(ShellClientFactory factory,
-                 string name,
-                 string user_id,
+                 Identity target,
                  CapabilityFilter filter,
                  PIDReceiver& pid_receiver) => (ConnectResult result);
 
   // The listener is removed when the |listener| pipe is closed.
   AddInstanceListener(InstanceListener listener);
 };