Use PageManager in About page

chrome/browser/ui/webui/options/chromeos/help_overlay_handler.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 CHROME_BROWSER_UI_WEBUI_OPTIONS_CHROMEOS_HELP_OVERLAY_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_OPTIONS_CHROMEOS_HELP_OVERLAY_HANDLER_H_
+

[Dan Beam, 2014/08/06 18:30:55]

#include "base/basictypes.h"
#include "base/macros.h"

[michaelpg, 2014/08/06 21:58:18]

Oops, these files should not be part of this CL, they aren't even being built.
This is Part 3, actually showing the overlay in Settings.

+#include "chrome/browser/ui/webui/options/options_ui.h"
+
+namespace chromeos {
+namespace options {
+
+// Help UI page handler for the options page when using Settings in a window
+// on Chrome OS. Defers to ::HelpHandler.
+class HelpOverlayHandler : public ::options::OptionsPageUIHandler {
+ public:
+  HelpOverlayHandler();
+  virtual ~HelpOverlayHandler();
+
+  // OptionsPageUIHandler implementation.
+  virtual void GetLocalizedValues(
+      base::DictionaryValue* localized_strings) OVERRIDE;
+
+  // WebUIMessageHandler implementation.
+  virtual void RegisterMessages() OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HelpOverlayHandler);
+};
+
+}  // namespace options
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_UI_WEBUI_OPTIONS_CHROMEOS_HELP_OVERLAY_HANDLER_H_