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

chrome/browser/resources/settings/languages_page/edit_dictionary_page.html

 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-a11y-keys/iron-a11y-keys.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-list/iron-list.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-input/paper-input.html">
+<link rel="import" href="../global_scroll_target_behavior.html">
 <link rel="import" href="../prefs/prefs.html">
 <link rel="import" href="../prefs/prefs_behavior.html">
 <link rel="import" href="../settings_shared_css.html">
 
 <dom-module id="settings-edit-dictionary-page">
   <template>
     <style include="settings-shared">
       :host {
         display: flex;
         flex-direction: column;
       }
 
       #newWord {
         width: var(--paper-input-max-width);
       }
 
-      iron-list {
-        /* TODO(michaelpg): Size to fit the viewport. */
-        height: 300px;
-      }
-
       iron-list .word {
         flex: 1;
       }
 
       paper-button {
         -webkit-margin-start: 16px;
       }
     </style>
     <div class="settings-box first">
       <iron-a11y-keys id="keys" keys="enter esc"
           on-keys-pressed="onKeysPress_"></iron-a11y-keys>
       <div class="start">
         <paper-input id="newWord" no-label-float value="{{newWordValue_}}"
             label="$i18n{addDictionaryWordLabel}"></paper-input>
       </div>
       <paper-button class="secondary-button" on-tap="onAddWordTap_"
           disabled="[[!validateWord_(newWordValue_)]]" id="addWord">
         $i18n{addDictionaryWordButton}
       </paper-button>
     </div>
     <div class="settings-box continuation block">
       <h2>$i18n{customDictionaryWords}</h2>
       <div class="list-frame">
         <template is="dom-if" if="[[hasWords_(words_.length)]]">
-          <iron-list id="list" items="{{words_}}">
+          <iron-list id="list" items="{{words_}}"
+              scroll-target="[[subpageScrollTarget]]">
             <template>
               <div class="list-item">
                 <div class="word text-elide">[[item]]</div>
                 <paper-icon-button icon="cr:clear" on-tap="onRemoveWordTap_"
                     tabindex$="[[tabIndex]]">
                 </paper-icon-button>
               </div>
             </template>
           </iron-list>
         </template>
         <template is="dom-if" if="[[!hasWords_(words_.length)]]">
           <div id="noWordsLabel" class="list-item">
             $i18n{noCustomDictionaryWordsFound}
           </div>
         </template>
       </div>
     </div>
   </template>
   <script src="edit_dictionary_page.js"></script>
 </dom-module>