Change userid from a uint32_t to a string guid

mojo/shell/public/cpp/connection.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_PUBLIC_CPP_CONNECTION_H_
 #define MOJO_SHELL_PUBLIC_CPP_CONNECTION_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 63 matching lines @@
   // same as the value returned by GetRemoveApplicationName().
   virtual const std::string& GetConnectionName() = 0;
 
   // Returns the name identifying the remote application on this connection.
   virtual const std::string& GetRemoteApplicationName() = 0;
 
   // Returns the User ID for the remote application. Prior to the Connect()
   // callback being fired, this will return the value passed via Connect().
   // After the Connect() callback (call AddRemoteIDCallback to register one)
   // this will return the actual user id the shell ran the target as.
-  virtual uint32_t GetRemoteUserID() const = 0;
+  virtual const std::string& GetRemoteUserID() const = 0;
 
   // Register a handler to receive an error notification on the pipe to the
   // remote application's InterfaceProvider.
   virtual void SetRemoteInterfaceProviderConnectionErrorHandler(
       const Closure& handler) = 0;
 
   // Returns the id of the remote application. For Connections created via
   // Shell::Connect(), this will not be determined until Connect()'s callback is
   // run, and this function will return false. Use AddRemoteIDCallback() to
   // schedule a callback to be run when the remote application id is available.
@@ skipping 17 matching lines @@
 
  protected:
   virtual InterfaceRegistry* GetLocalRegistry() = 0;
 
   virtual base::WeakPtr<Connection> GetWeakPtr() = 0;
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_SHELL_PUBLIC_CPP_CONNECTION_H_