Change userid from a uint32_t to a string guid

mojo/shell/tests/connect/connect_test_app.cc

 // 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.
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
@@ skipping 16 matching lines @@
                        public test::mojom::ConnectTestService,
                        public test::mojom::StandaloneApp,
                        public test::mojom::BlockedInterface {
  public:
   ConnectTestApp() {}
   ~ConnectTestApp() override {}
 
  private:
   // mojo::ShellClient:
   void Initialize(Connector* connector, const std::string& name,
-                  uint32_t id, uint32_t user_id) override {
+                  const std::string& user_id, uint32_t id) override {
     connector_ = connector;
     name_ = name;
     id_ = id;
     userid_ = user_id;
     bindings_.set_connection_error_handler(
         base::Bind(&ConnectTestApp::OnConnectionError,
                    base::Unretained(this)));
     standalone_bindings_.set_connection_error_handler(
         base::Bind(&ConnectTestApp::OnConnectionError,
                    base::Unretained(this)));
@@ skipping 86 matching lines @@
   }
 
   void OnConnectionError() {
     if (bindings_.empty() && standalone_bindings_.empty())
       base::MessageLoop::current()->QuitWhenIdle();
   }
 
   Connector* connector_ = nullptr;
   std::string name_;
   uint32_t id_ = mojom::Connector::kInvalidApplicationID;
-  uint32_t userid_ = mojom::Connector::kUserRoot;
+  std::string userid_ = mojom::kRootUserID;
   BindingSet<test::mojom::ConnectTestService> bindings_;
   BindingSet<test::mojom::StandaloneApp> standalone_bindings_;
   BindingSet<test::mojom::BlockedInterface> blocked_bindings_;
   test::mojom::ExposedInterfacePtr caller_;
 
   DISALLOW_COPY_AND_ASSIGN(ConnectTestApp);
 };
 
 }  // namespace shell
 }  // namespace mojo
 
 
 MojoResult MojoMain(MojoHandle shell_handle) {
   MojoResult rv = mojo::ApplicationRunner(
       new mojo::shell::ConnectTestApp).Run(shell_handle);
   return rv;
 }