Add MarkRole in blink side to expose mark tag properly

Source/modules/accessibility/AXObject.cpp

 /*
  * Copyright (C) 2008, 2009, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 173 matching lines @@
     { LabelRole, "Label" },
     { LegendRole, "Legend" },
     { LinkRole, "Link" },
     { ListBoxOptionRole, "ListBoxOption" },
     { ListBoxRole, "ListBox" },
     { ListItemRole, "ListItem" },
     { ListMarkerRole, "ListMarker" },
     { ListRole, "List" },
     { LogRole, "Log" },
     { MainRole, "Main" },
+    { MarkRole, "Mark" },
     { MarqueeRole, "Marquee" },
     { MathRole, "Math" },
     { MenuBarRole, "MenuBar" },
     { MenuButtonRole, "MenuButton" },
     { MenuItemRole, "MenuItem" },
     { MenuItemCheckBoxRole, "MenuItemCheckBox" },
     { MenuItemRadioRole, "MenuItemRadio" },
     { MenuListOptionRole, "MenuListOption" },
     { MenuListPopupRole, "MenuListPopup" },
     { MenuRole, "Menu" },
@@ skipping 1267 matching lines @@
 }
 
 const AtomicString& AXObject::internalRoleName(AccessibilityRole role)
 {
     static const Vector<AtomicString>* internalRoleNameVector = createInternalRoleNameVector();
 
     return internalRoleNameVector->at(role);
 }
 
 } // namespace blink