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

mojo/shell/application_manager.h

 // Copyright 2014 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_APPLICATION_MANAGER_H_
 #define MOJO_SHELL_APPLICATION_MANAGER_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 178 matching lines @@
   base::TaskRunner* task_runner_;
   scoped_ptr<NativeRunnerFactory> native_runner_factory_;
   std::vector<scoped_ptr<NativeRunner>> native_runners_;
   scoped_ptr<ShellConnection> shell_connection_;
   WeakBindingSet<mojom::ApplicationManager> bindings_;
   base::WeakPtrFactory<ApplicationManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ApplicationManager);
 };
 
-mojom::Shell::ConnectCallback EmptyConnectCallback();
+mojom::Connector::ConnectCallback EmptyConnectCallback();
 
 }  // namespace shell
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_APPLICATION_MANAGER_H_