Adds AX role for abbr tag.

chrome/common/extensions/api/automation.idl

 // Copyright 2014 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.
 
 // The <code>chrome.automation</code> API allows developers to access the
 // automation (accessibility) tree for the browser. The tree resembles the DOM
 // tree, but only exposes the <em>semantic</em> structure of a page. It can be
 // used to programmatically interact with a page by examining names, roles, and
 // states, listening for events, and performing actions on nodes.
 [nocompile] namespace automation {
@@ skipping 35 matching lines @@
     selectionRemove,
     show,
     textChanged,
     textSelectionChanged,
     treeChanged,
     valueChanged
   };
 
   // Describes the purpose of an $(ref:automation.AutomationNode).
   enum RoleType {
+    abbr,
     alertDialog,
     alert,
     annotation,
     application,
     article,
     banner,
     blockquote,
     busyIndicator,
     button,
     buttonDropDown,
@@ skipping 565 matching lines @@
     // Everything in the tree between the two node/offset pairs gets included
     // in the selection. The anchor is where the user started the selection,
     // while the focus is the point at which the selection gets extended
     // e.g. when dragging with a mouse or using the keyboard. For nodes with
     // the role staticText, the offset gives the character offset within
     // the value where the selection starts or ends, respectively.
     [nocompile] static void setDocumentSelection(
         SetDocumentSelectionParams params);
   };
 };