Remove remaining non-MD Ash accessibility UI code

ash/common/system/tray_accessibility.h

Index: ash/common/system/tray_accessibility.h
diff --git a/ash/common/system/tray_accessibility.h b/ash/common/system/tray_accessibility.h
index 1b549626d55556b8527fd82e5f39aff687990b24..79161797e1c4aaf9b4ed92e38c9dcefde7948eec 100644
--- a/ash/common/system/tray_accessibility.h
+++ b/ash/common/system/tray_accessibility.h
@@ -75,11 +75,7 @@ class AccessibilityDetailedView : public TrayDetailsView,
   // 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.
+  // Helper function to create entries in the detailed accessibility view.
   HoverHighlightView* AddScrollListItem(const base::string16& text,
                                         bool highlight,
                                         bool checked,