Get rid of AX_LINE_BREAKS attribute to improve performance.

chrome/renderer/resources/extensions/automation/automation_node.js

 // 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.
 
 var AutomationEvent = require('automationEvent').AutomationEvent;
 var automationInternal =
     require('binding').Binding.create('automationInternal').generate();
 var exceptionHandler = require('uncaught_exception_handler');
 var IsInteractPermitted =
     requireNative('automationInternal').IsInteractPermitted;
@@ skipping 132 matching lines @@
  * @param {number} endIndex The end index of the range.
  * @return {?automation.Rect} The bounding box of the subrange of this node,
  *     or the location if there are no subranges, or undefined if
  *     the tree or node wasn't found.
  */
 var GetBoundsForRange = requireNative('automationInternal').GetBoundsForRange;
 
 /**
  * @param {number} axTreeID The id of the accessibility tree.
  * @param {number} nodeID The id of a node.
+ * @return {!Array.<number>} The text offset where each line starts, or an empty
+ *     array if this node has no text content, or undefined if the tree or node
+ *     was not found.
+ */
+var GetLineStartOffsets = requireNative(
+    'automationInternal').GetLineStartOffsets;
+
+/**
+ * @param {number} axTreeID The id of the accessibility tree.
+ * @param {number} nodeID The id of a node.
  * @param {string} attr The name of a string attribute.
  * @return {?string} The value of this attribute, or undefined if the tree,
  *     node, or attribute wasn't found.
  */
 var GetStringAttribute = requireNative('automationInternal').GetStringAttribute;
 
 /**
  * @param {number} axTreeID The id of the accessibility tree.
  * @param {number} nodeID The id of a node.
  * @param {string} attr The name of an attribute.
@@ skipping 97 matching lines @@
   },
 
   boundsForRange: function(startIndex, endIndex) {
     return GetBoundsForRange(this.treeID, this.id, startIndex, endIndex);
   },
 
   get indexInParent() {
     return GetIndexInParent(this.treeID, this.id);
   },
 
+  get lineStartOffsets() {
+    return GetLineStartOffsets(this.treeID, this.id);
+  },
+
   get childTree() {
     var childTreeID = GetIntAttribute(this.treeID, this.id, 'childTreeId');
     if (childTreeID)
       return AutomationRootNodeImpl.get(childTreeID);
   },
 
   get firstChild() {
     if (!this.rootImpl)
       return undefined;
     if (this.childTree)
@@ skipping 400 matching lines @@
 
 var nodeRefAttributes = [
     ['activedescendantId', 'activeDescendant'],
     ['tableColumnHeaderId', 'tableColumnHeader'],
     ['tableHeaderId', 'tableHeader'],
     ['tableRowHeaderId', 'tableRowHeader'],
     ['titleUiElement', 'titleUIElement']];
 
 var intListAttributes = [
     'characterOffsets',
-    'lineBreaks',
     'markerEnds',
     'markerStarts',
     'markerTypes',
     'wordEnds',
     'wordStarts'];
 
 var nodeRefListAttributes = [
     ['cellIds', 'cells'],
     ['controlsIds', 'controls'],
     ['describedbyIds', 'describedBy'],
@@ skipping 329 matching lines @@
       'firstChild',
       'lastChild',
       'children',
       'previousSibling',
       'nextSibling',
       'isRootNode',
       'role',
       'state',
       'location',
       'indexInParent',
+      'lineStartOffsets',
       'root',
       'htmlAttributes',
   ]),
 });
 
 function AutomationRootNode() {
   privates(AutomationRootNode).constructPrivate(this, arguments);
 }
 utils.expose(AutomationRootNode, AutomationRootNodeImpl, {
   superclass: AutomationNode,
@@ skipping 16 matching lines @@
 utils.defineProperty(AutomationRootNode, 'getOrCreate', function(treeID) {
   return AutomationRootNodeImpl.getOrCreate(treeID);
 });
 
 utils.defineProperty(AutomationRootNode, 'destroy', function(treeID) {
   AutomationRootNodeImpl.destroy(treeID);
 });
 
 exports.$set('AutomationNode', AutomationNode);
 exports.$set('AutomationRootNode', AutomationRootNode);