Change userid from a uint32_t to a string guid

mash/task_viewer/task_viewer.cc

 // Copyright 2015 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 "mash/task_viewer/task_viewer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
@@ skipping 242 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(TaskViewerContents);
 };
 
 }  // namespace
 
 TaskViewer::TaskViewer() {}
 TaskViewer::~TaskViewer() {}
 
 void TaskViewer::Initialize(mojo::Connector* connector,
                             const std::string& url,
-                            uint32_t id, uint32_t user_id) {
+                            const std::string& user_id,
+                            uint32_t id) {
   tracing_.Initialize(connector, url);
 
   aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
   views::WindowManagerConnection::Create(connector);
 
   mojo::shell::mojom::ShellPtr shell;
   connector->ConnectToInterface("mojo:shell", &shell);
 
   mojo::shell::mojom::InstanceListenerPtr listener;
   mojo::shell::mojom::InstanceListenerRequest request = GetProxy(&listener);
   shell->AddInstanceListener(std::move(listener));
 
   package_manager::mojom::CatalogPtr catalog;
   connector->ConnectToInterface("mojo:package_manager", &catalog);
 
   TaskViewerContents* task_viewer = new TaskViewerContents(
       std::move(request), std::move(catalog));
   views::Widget* window = views::Widget::CreateWindowWithBounds(
       task_viewer, gfx::Rect(10, 10, 500, 500));
   window->Show();
 }
 
 }  // namespace task_viewer
 }  // namespace main