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diff --git a/chromium/chrome/browser/resources/chromeos/chromevox/common/group_util.js b/chromium/chrome/browser/resources/chromeos/chromevox/common/group_util.js
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+// 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.
+
+/**
+ * @fileoverview Some utilities for defining what groups are.
+ */
+
+
+goog.provide('cvox.GroupUtil');
+
+goog.require('cvox.AriaUtil');
+goog.require('cvox.DomUtil');
+
+
+/**
+ * If a node contains more characters than this, it should not be treated
+ * as a leaf node by the smart navigation algorithm.
+ *
+ * This number was determined by looking at the average number of
+ * characters in a paragraph:
+ * http://www.fullondesign.co.uk/design/usability/
+ * 285-how-many-characters-per-a-page-is-normal.htm
+ * and then trying it out on a few popular websites (CNN, BBC,
+ * Google Search, etc.) and making sure it made sense.
+ * @type {number}
+ * @private
+ * @const
+ */
+cvox.GroupUtil.MAX_CHARCOUNT_ = 1500;
+
+
+/**
+ * If a node contains any of these elements, it should not be treated
+ * as a leaf node by the smart navigation algorithm.
+ * @type {string}
+ * @private
+ * @const
+ */
+cvox.GroupUtil.BREAKOUT_SELECTOR_ = 'blockquote,' +
+    'button,' +
+    'code,' +
+    'form,' +
+    'frame,' +
+    'h1,' +
+    'h2,' +
+    'h3,' +
+    'h4,' +
+    'h5,' +
+    'h6,' +
+    'hr,' +
+    'iframe,' +
+    'input,' +
+    'object,' +
+    'ol,' +
+    'p,' +
+    'pre,' +
+    'select,' +
+    'table,' +
+    'tr,' +
+    'ul,' +
+    'math,' +
+  // This takes care of MathJax expressions.
+    'span.math,' +
+// TODO (sorge) Do we want to group all math or only display math?
+//    '[mode="display"],' +
+    // Aria widget roles
+    '[role~="alert ' +
+    'alertdialog ' +
+    'button ' +
+    'checkbox ' +
+    'combobox ' +
+    'dialog ' +
+    'log ' +
+    'marquee ' +
+    'menubar ' +
+    'progressbar ' +
+    'radio ' +
+    'radiogroup ' +
+    'scrollbar ' +
+    'slider ' +
+    'spinbutton ' +
+    'status ' +
+    'tab ' +
+    'tabpanel ' +
+    'textbox ' +
+    'toolbar ' +
+    'tooltip ' +
+    'treeitem ' +
+    // Aria structure roles
+    'article ' +
+    'document ' +
+    'group ' +
+    'heading ' +
+    'img ' +
+    'list ' +
+    'math ' +
+    'region ' +
+    'row ' +
+    'separator"]';
+
+
+/**
+ * Returns true if this is a leaf node for groups.
+ * true for a node => true for all child nodes
+ * true if node has no children
+ * @param {!Node} node The node to check.
+ * @return {boolean} true if this is at the "leaf node" level or lower
+ * for this granularity.
+ */
+cvox.GroupUtil.isLeafNode = function(node) {
+  // TODO (stoarca): Write test to make sure that this function satisfies
+  // the restriction given above.
+  if (node.tagName == 'LABEL') {
+    return cvox.DomUtil.isLeafNode(node);
+  }
+  if (cvox.DomUtil.isLeafNode(node)) {
+    return true;
+  }
+
+  if (!cvox.DomUtil.isSemanticElt(node)) {
+    var breakingNodes = node.querySelectorAll(
+        cvox.GroupUtil.BREAKOUT_SELECTOR_);
+
+    for (var i = 0; i < breakingNodes.length; ++i) {
+      if (cvox.DomUtil.hasContent(breakingNodes[i])) {
+        return false;
+      }
+    }
+  }
+
+  if (cvox.AriaUtil.isCompositeControl(node) &&
+      !cvox.DomUtil.isFocusable(node)) {
+    return false;
+  }
+
+  var content = cvox.DomUtil.collapseWhitespace(
+      cvox.DomUtil.getValue(node) + ' ' +
+      cvox.DomUtil.getName(node));
+  if (content.length > cvox.GroupUtil.MAX_CHARCOUNT_) {
+    return false;
+  }
+
+  if (content.replace(/\s/g, '') === '') {
+    // Text only contains whitespace
+    return false;
+  }
+
+  return true;
+};