Help: Implement the initial version of the cross-platform help/about page.

chrome/browser/ui/webui/help/help_handler.h

+// Copyright (c) 2012 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 CHROME_BROWSER_UI_WEBUI_HELP_HELP_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_HELP_HELP_HANDLER_H_
+
+#include <string>
+
+#include "base/compiler_specific.h"
+#include "chrome/browser/ui/webui/help/version_updater.h"
+#include "content/public/browser/web_ui_message_handler.h"
+
+// WebUI message handler for the help page.
+class HelpHandler : public content::WebUIMessageHandler {
+ public:
+  HelpHandler();
+  virtual ~HelpHandler();
+
+  // WebUIMessageHandler implementation.
+  virtual void RegisterMessages() OVERRIDE;
+
+  // Fills |localized_strings| with string values for the UI.
+  void GetLocalizedValues(base::DictionaryValue* localized_strings);
+
+ private:
+  // Initiates the update process.
+  void CheckForUpdate(const base::ListValue* args);
+
+  // Relaunches the browser.
+  void RelaunchNow(const base::ListValue* args);
+
+  // Callback method which forwards status updates to the page.
+  void UpdateStatus(VersionUpdater::Status status, int progress);
+
+  // Specialized instance of the VersionUpdater used to update the browser.
+  scoped_ptr<VersionUpdater> version_updater_;
+
+  DISALLOW_COPY_AND_ASSIGN(HelpHandler);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_HELP_HELP_HANDLER_H_