Refactor AddScrollListItem() in system menu detailed views

ash/system/tray_accessibility.h

Index: ash/system/tray_accessibility.h
diff --git a/ash/system/tray_accessibility.h b/ash/system/tray_accessibility.h
index e3a2e1a6434471ece8b565dd0075f874c229dff8..2e101f9d5b6d7d6b604e64cda38a90be4aaf45f8 100644
--- a/ash/system/tray_accessibility.h
+++ b/ash/system/tray_accessibility.h
@@ -8,7 +8,6 @@
 #include <stdint.h>
 
 #include "ash/accessibility_delegate.h"
-#include "ash/shell_observer.h"
 #include "ash/system/accessibility_observer.h"
 #include "ash/system/tray/tray_details_view.h"
 #include "ash/system/tray/tray_image_item.h"
@@ -21,10 +20,6 @@ namespace chromeos {
 class TrayAccessibilityTest;
 }
 
-namespace gfx {
-struct VectorIcon;
-}
-
 namespace views {
 class Button;
 class CustomButton;
@@ -33,7 +28,6 @@ class View;
 }
 
 namespace ash {
-class HoverHighlightView;
 class SystemTrayItem;
 
 namespace tray {
@@ -60,8 +54,7 @@ class AccessibilityPopupView : public views::View {
 };
 
 // Create the detailed view of accessibility tray.
-class AccessibilityDetailedView : public TrayDetailsView,
-                                  public ShellObserver {
+class AccessibilityDetailedView : public TrayDetailsView {
  public:
   explicit AccessibilityDetailedView(SystemTrayItem* owner);
   ~AccessibilityDetailedView() override {}
@@ -82,15 +75,6 @@ class AccessibilityDetailedView : public TrayDetailsView,
   // Add the accessibility feature list.
   void AppendAccessibilityList();
 
-  // Helper function to create entries in the detailed accessibility view.
-  HoverHighlightView* AddScrollListItem(const base::string16& text,
-                                        bool checked,
-                                        const gfx::VectorIcon& icon);
-  HoverHighlightView* AddScrollListItemWithoutIcon(const base::string16& text,
-                                                   bool checked);
-
-  void AddSubHeader(const base::string16& header_text);
-
   views::View* spoken_feedback_view_ = nullptr;
   views::View* high_contrast_view_ = nullptr;
   views::View* screen_magnifier_view_ = nullptr;