Seperate horizontal and vertical overscrolling

chrome/browser/resources/gesture_config.js

 // Copyright (c) 2013 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.
 
 // Redefine '$' here rather than including 'cr.js', since this is
 // the only function needed.  This allows this file to be loaded
 // in a browser directly for layout and some testing purposes.
 var $ = function(id) { return document.getElementById(id); };
 
 /**
@@ skipping 313 matching lines @@
       label: 'Complete when overscrolled (horizontal)',
       units: '%'
     },
     {
       key: 'vertical_threshold_complete',
       label: 'Complete when overscrolled (vertical)',
       units: '%'
     },
     {
       key: 'minimum_threshold_start',
-      label: 'Start overscroll gesture after scrolling',
+      label: 'Start overscroll gesture (horizontal)',
       units: 'pixels'
     },
     {
+      key: 'vertical_threshold_start',
+      label: 'Start overscroll gesture (vertical)',
+      units: 'pixels'
+    },
+    {
       key: 'horizontal_resist_threshold',
       label: 'Start resisting overscroll after (horizontal)',
       units: 'pixels'
     },
     {
       key: 'vertical_resist_threshold',
       label: 'Start resisting overscroll after (vertical)',
       units: 'pixels'
     },
   ];
@@ skipping 237 matching lines @@
    */
   updatePreferenceValueResult: function(prefName, value, isDefault) {
     prefName = prefName.substring(prefName.indexOf('.') + 1);
     $(prefName).value = value;
     this.updateResetButton($(prefName + '-reset'), isDefault);
     this.updateResetAllButton(this.areAllPrefsSetToDefault());
   },
 };
 
 document.addEventListener('DOMContentLoaded', gesture_config.initialize);