1 files changed, 32 insertions, 0 deletions
diff --git a/chromium/chrome/browser/resources/chromeos/chromevox/common/string_util.js b/chromium/chrome/browser/resources/chromeos/chromevox/common/string_util.js
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index 00000000000..5b771c5a774
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+++ b/chromium/chrome/browser/resources/chromeos/chromevox/common/string_util.js
@@ -0,0 +1,32 @@
+// Copyright 2015 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 Utilities for strings.
+ */
+
+goog.provide('StringUtil');
+
+/**
+ * @constructor
+ */
+StringUtil = function() {};
+
+/**
+ * Returns the length of the longest common prefix of two strings.
+ * @param {string} first The first string.
+ * @param {string} second The second string.
+ * @return {number} The length of the longest common prefix, which may be 0
+ *     for an empty common prefix.
+ */
+StringUtil.longestCommonPrefixLength = function(first, second) {
+  var limit = Math.min(first.length, second.length);
+  var i;
+  for (i = 0; i < limit; ++i) {
+    if (first.charAt(i) != second.charAt(i)) {
+      break;
+    }
+  }
+  return i;
+};