Skip over the URL input when the NTP is used for the Home Button.

chrome/browser/resources/settings/controls/settings_input.js

 // 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
  * `settings-input` is a single-line text field for user input associated
  * with a pref value.
  */
 Polymer({
@@ skipping 18 matching lines @@
       notify: true,
     },
 
     /* Set to true to disable editing the input. */
     disabled: {
       type: Boolean,
       value: false,
       reflectToAttribute: true
     },
 
+    canTab: Boolean,
+
     /* Properties for paper-input. This is not strictly necessary.
      * Though it does define the types for the closure compiler. */
     errorMessage: { type: String },
     label: { type: String },
     noLabelFloat: { type: Boolean, value: false },
     pattern: { type: String },
     readonly: { type: Boolean, value: false },
     required: { type: Boolean, value: false },
     stopKeyboardEventPropagation: { type: Boolean, value: false },
     type: { type: String },
@@ skipping 22 matching lines @@
     if (this.pref.type == chrome.settingsPrivate.PrefType.NUMBER) {
       this.value = this.pref.value.toString();
     } else {
       assert(this.pref.type == chrome.settingsPrivate.PrefType.STRING ||
              this.pref.type == chrome.settingsPrivate.PrefType.URL);
       this.value = /** @type {string} */(this.pref.value);
     }
   },
 
   /**
+   * Gets a tab index for this control if it can be tabbed to.
+   * @param {boolean} canTab
+   * @return {number}
+   * @private
+   */
+  getTabindex_: function(canTab) {
+    return canTab ? 0 : -1;
+  },
+
+  /**
    * Blur method for paper-input. Only update the pref value on a blur event.
    * @private
    */
   onBlur_: function() {
     if (!this.pref)
       return;
 
     if (this.pref.type == chrome.settingsPrivate.PrefType.NUMBER) {
       if (!this.value) {
         // Ignore empty input field and restore value.
@@ skipping 16 matching lines @@
   /**
    * @param {boolean} disabled
    * @param {!chrome.settingsPrivate.PrefObject} pref
    * @return {boolean} Whether the element should be disabled.
    * @private
    */
   isDisabled_: function(disabled, pref) {
     return disabled || this.isPrefPolicyControlled(pref);
   },
 });