Change userid from a uint32_t to a string guid

mash/init/init.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 MASH_INIT_INIT_H_
 #define MASH_INIT_INIT_H_
 
 #include <map>
 
 #include "base/callback.h"
@@ skipping 14 matching lines @@
 class Init : public mojo::ShellClient,
              public mojom::Login,
              public mojo::InterfaceFactory<mojom::Login> {
  public:
   Init();
   ~Init() override;
 
  private:
   // mojo::ShellClient:
   void Initialize(mojo::Connector* connector, const std::string& url,
-                  uint32_t id, uint32_t user_id) override;
+                  const std::string& user_id, uint32_t id) override;
 
   // mojom::Login:
-  void LoginAs(uint32_t user_id) override;
+  void LoginAs(const mojo::String& user_id) override;
 
   // mojo::InterfaceFactory<mojom::Login>:
   void Create(mojo::Connection* connection,
               mojom::LoginRequest request) override;
 
   void StartWindowManager();
   void StartLogin();
 
   // Starts the application at |url|, running |restart_callback| if the
   // connection to the application is closed.
   void StartRestartableService(mojo::Connector::ConnectParams* params,
                                const base::Closure& restart_callback);
 
   mojo::Connector* connector_;
   std::map<std::string, scoped_ptr<mojo::Connection>> connections_;
   mojo::BindingSet<mojom::Login> login_bindings_;
   scoped_ptr<mojo::Connection> mus_connection_;
 
   DISALLOW_COPY_AND_ASSIGN(Init);
 };
 
 }  // namespace init
 }  // namespace mash
 
 #endif  // MASH_INIT_INIT_H_