Make BaseView et al. take an ApplicationConnector instead of an ApplicationImpl.

mojo/public/cpp/application/connect.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.
 
 // Helpers for using |ServiceProvider|s.
 
 #ifndef MOJO_PUBLIC_CPP_APPLICATION_CONNECT_H_
 #define MOJO_PUBLIC_CPP_APPLICATION_CONNECT_H_
 
 #include "mojo/public/cpp/bindings/interface_handle.h"
@@ skipping 45 matching lines @@
   ServiceProviderPtr service_provider;
   application_connector->ConnectToApplication(
       application_url, GetProxy(&service_provider), nullptr);
   ConnectToService(service_provider.get(), request.Pass());
 }
 
 // Helper for getting an |InterfaceHandle<ApplicationConnector>| (which can be
 // passed to any thread) from the shell.
 InterfaceHandle<ApplicationConnector> CreateApplicationConnector(Shell* shell);
 
+// Helper for "duplicating" a |ApplicationConnector| (typically, from an
+// |ApplicationConnectorPtr|, getting another independent
+// |InterfaceHandle<ApplicationConnector>|).
+InterfaceHandle<ApplicationConnector> DuplicateApplicationConnector(
+    ApplicationConnector* application_connector);
+
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_APPLICATION_CONNECT_H_