Implement all system menu title row buttons for Ash MD

ash/common/system/tray_accessibility.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 ASH_COMMON_SYSTEM_TRAY_ACCESSIBILITY_H_
 #define ASH_COMMON_SYSTEM_TRAY_ACCESSIBILITY_H_
 
 #include <stdint.h>
 
 #include "ash/common/accessibility_delegate.h"
@@ skipping 46 matching lines @@
                                   public ShellObserver {
  public:
   AccessibilityDetailedView(SystemTrayItem* owner, LoginStatus login);
   ~AccessibilityDetailedView() override {}
 
  private:
   // TrayDetailsView:
   void HandleViewClicked(views::View* view) override;
   void HandleButtonPressed(views::Button* sender,
                            const ui::Event& event) override;
-  void ShowSettings() override;
+  void CreateExtraTitleRowButtons() override;
+
+  // Launches the WebUI settings in a browser and closes the system menu.
+  void ShowSettings();
+
+  // Launches the a11y help article in a browser and closes the system menu.
+  void ShowHelp();
 
   // Add the accessibility feature list.
   void AppendAccessibilityList();
 
   // Add help entries. Only used for non-MD.
   void AppendHelpEntries();
 
   // Helper function to create entries in the detailed accessibility view. The
   // |icon| parameter is used to create button icons for MD only.
   HoverHighlightView* AddScrollListItem(const base::string16& text,
@@ skipping 62 matching lines @@
   // A11y feature status on just entering the lock screen.
   bool show_a11y_menu_on_lock_screen_;
 
   friend class chromeos::TrayAccessibilityTest;
   DISALLOW_COPY_AND_ASSIGN(TrayAccessibility);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_ACCESSIBILITY_H_