Add code to initialize accessibility for UI in the ChromeOS startup wizard.

chrome/browser/chromeos/login/wizard_accessibility_helper.h

+// Copyright (c) 2010 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_CHROMEOS_LOGIN_WIZARD_ACCESSIBILITY_HELPER_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_WIZARD_ACCESSIBILITY_HELPER_H_
+#pragma once
+
+#include "base/keyboard_codes.h"
+#include "base/scoped_ptr.h"
+#include "base/singleton.h"
+#include "chrome/browser/chromeos/login/wizard_accessibility_handler.h"
+#include "chrome/browser/views/accessible_view_helper.h"
+#include "chrome/common/notification_registrar.h"
+
+class Profile;
+namespace views {
+class View;
+}
+
+// Class that provides convenience methods to enable accessibility for a
+// specified View.
+class WizardAccessibilityHelper {
+ public:
+  // Get Singleton instance of WizardAccessibilityHelper.
+  static WizardAccessibilityHelper* GetInstance();
+
+  // Enables Accessibility by setting the accessibility pref and
+  // registering the specified view_tree to raise UI notifications.
+  void EnableAccessibility(views::View* view_tree, Profile* profile);
+
+  // Enabled accessibility for the specified view_tree if the
+  // accessibility pref is already set.
+  void MaybeEnableAccessibility(views::View* view_tree, Profile* profile);
+
+  // Keyboard accelerator key to enable accessibility.
+  static const base::KeyboardCode accelerator = base::VKEY_Z;
+
+ private:
+  friend struct DefaultSingletonTraits<WizardAccessibilityHelper>;
+  WizardAccessibilityHelper();
+  ~WizardAccessibilityHelper() {}
+
+  scoped_ptr<AccessibleViewHelper> accessible_view_helper_;
+
+  scoped_ptr<WizardAccessibilityHandler> accessibility_handler_;
+
+  // Used for tracking registrations to accessibility notifications.
+  NotificationRegistrar registrar_;
+
+  DISALLOW_COPY_AND_ASSIGN(WizardAccessibilityHelper);
+};
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_WIZARD_ACCESSIBILITY_HELPER_H_