Also delete plugin data when the cookies checkbox in the clear browsing data dialog is checked.

chrome/browser/resources/options/clear_browser_data.html

 <div class="page hidden" id="clearBrowserDataPage">
   <h1 i18n-content="clearBrowsingDataTitle"></h1>
   <section>
     <h3 i18n-content="clearBrowsingDataSectionHeader"></h3>
     <div>
       <span i18n-content="clearBrowsingDataLabel"></span>
       <select id="clearBrowsingDataTimePeriod"
           i18n-options="clearBrowsingDataTimeList"
           pref="browser.clear_data.time_period"
           dataType='number'>
@@ skipping 10 matching lines @@
           <span i18n-content="deleteDownloadHistoryCheckbox"></span>
         </label>
         <label class="checkbox">
           <input id="deleteCacheCheckbox"
               pref="browser.clear_data.cache" type="checkbox">
           <span i18n-content="deleteCacheCheckbox"></span>
         </label>
         <label class="checkbox">
           <input id="deleteCookiesCheckbox"
               pref="browser.clear_data.cookies" type="checkbox">
-          <span i18n-content="deleteCookiesCheckbox"></span>
+          <span id="deleteCookiesLabel"></span>
         </label>
         <label class="checkbox">
           <input id="deletePasswordsCheckbox"
               pref="browser.clear_data.passwords" type="checkbox">
           <span i18n-content="deletePasswordsCheckbox"></span>
         </label>
         <label class="checkbox">
           <input id="deleteFormDataCheckbox"
               pref="browser.clear_data.form_data" type="checkbox">
           <span i18n-content="deleteFormDataCheckbox"></span>
         </label>
       </div>
       <button id="clearBrowsingDataCommit"
               i18n-content="clearBrowsingDataCommit">
       </button>
       <span id="cbdThrobber"></span>
       <hr>
       <a target="_blank" i18n-content="flash_storage_settings"
           i18n-values="href:flash_storage_url"></a>
     </div>
   </section>
 </div>