Support output for Chrome's native find in ChromeVox.

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 310 matching lines @@
 
     // The type of change.
     TreeChangeType type;
   };
 
   // Possible tree changes to listen to using addTreeChangeObserver.
   // Note that listening to all tree changes can be expensive.
   enum TreeChangeObserverFilter {
     noTreeChanges,
     liveRegionTreeChanges,
+    textMarkerChanges,
     allTreeChanges
   };
 
   // A listener for changes on the <code>AutomationNode</code> tree.
   callback TreeChangeObserver = void(TreeChange treeChange);
 
   // A single node in an Automation tree.
   [nocompile, noinline_doc] dictionary AutomationNode {
     // The root node of the tree containing this AutomationNode.
     AutomationNode root;
@@ skipping 303 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);
   };
 };