Remove unused assets, update old assets

chrome/browser/resources/options/import_data_overlay.html

 <div id="import-data-overlay" class="page" hidden>
   <div class="close-button"></div>
   <h1 i18n-content="importDataOverlay"></h1>
   <div class="content-area">
     <div class="import-data-configure">
       <div id="import-from-div">
         <span i18n-content="importFromLabel"></span>
         <select id="import-browsers">
           <option i18n-content="importLoading"></option>
         </select>
@@ skipping 56 matching lines @@
           </label>
           <span class="controlled-setting-indicator"
               pref="import_autofill_form_data"></span>
         </div>
       </div>
     </div>
     <div class="import-data-success" hidden>
       <div id="import-success-header">
         <strong i18n-content="importSucceeded"></strong>
       </div>
-      <div id="import-success-image">
-        <img src="../../../../ui/webui/resources/images/success.png">
-      </div>
+      <div id="import-success-image"></div>
       <div id="import-find-your-bookmarks">
         <span i18n-content="findYourImportedBookmarks"></span>
         <div class="checkbox controlled-setting-with-label">
           <label>
             <input id="import-data-show-bookmarks-bar"
                 pref="bookmark_bar.show_on_all_tabs"
                 metric="Options_ShowBookmarksBar" type="checkbox">
             <span>
               <span i18n-content="toolbarShowBookmarksBar"></span>
               <span class="controlled-setting-indicator"
@@ skipping 22 matching lines @@
       <div class="action-area-right">
         <div class="button-strip">
           <button id="import-data-confirm" class="default-button"
               i18n-content="done">
           </button>
         </div>
       </div>
     </div>
   </div>
 </div>