[MD settings] set scroll target for custom word spellings subpage

chrome/browser/resources/settings/languages_page/edit_dictionary_page.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-edit-dictionary-page' is a sub-page for editing
  * the "dictionary" of custom words used for spell check.
  */
 Polymer({
   is: 'settings-edit-dictionary-page',
 
+  behaviors: [settings.GlobalScrollTargetBehavior],
+
   properties: {
     /** @private {string} */
     newWordValue_: String,
 
+    /**
+     * Needed by GlobalScrollTargetBehavior.
+     * @override
+     */
+    subpageRoute: {
+      type: Object,
+      value: settings.Route.EDIT_DICTIONARY,
+    },
+
     /** @private {!Array<string>} */
     words_: {
       type: Array,
       value: function() { return []; },
     },
   },
 
   /** @type {LanguageSettingsPrivate} */
   languageSettingsPrivate: null,
 
@@ skipping 97 matching lines @@
 
   /**
    * Checks if any words exists in the dictionary.
    * @private
    * @return {boolean}
    */
   hasWords_: function() {
     return this.words_.length > 0;
   }
 });