MD History: Add routing for grouped history mode.

chrome/browser/resources/md_history/history_toolbar.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_lazy_render/cr_lazy_render.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_toolbar/cr_toolbar.html">
 <link rel="import" href="chrome://history/browser_service.html">
 <link rel="import" href="chrome://history/icons.html">
 <link rel="import" href="chrome://history/shared_style.html">
 
 <!-- Lazy loaded: iron-dropdown, paper-button, paper-icon-button-light,
@@ skipping 216 matching lines @@
           <paper-tab value="2">$i18n{rangeMonth}</paper-tab>
         </paper-tabs>
         <div id="grouped-nav-container">
           <span id="grouped-date">
             [[getHistoryInterval_(queryInfo)]]
           </span>
           <button is="paper-icon-button-light"
               id="today-button"
               class="icon-button"
               title="$i18n{rangeToday}"
-              on-tap="onTodayTap_"
+              on-click="onTodayTap_"
               disabled="[[isToday_(groupedOffset)]]">
             <iron-icon icon="history:today"></iron-icon>
           </button>
           <button is="paper-icon-button-light"
               id="prev-button"
               title="$i18n{rangePrevious}"
               class="icon-button rtl-reversible"
-              on-tap="onPrevTap_"
+              on-click="onPrevTap_"
               disabled="[[!hasMoreResults]]">
             <iron-icon icon="history:chevron-left"></iron-icon>
           </button>
           <button is="paper-icon-button-light"
               id="next-button"
               title="$i18n{rangeNext}"
               class="icon-button rtl-reversible"
-              on-tap="onNextTap_"
+              on-click="onNextTap_"
               disabled="[[isToday_(groupedOffset)]]">
             <iron-icon icon="cr:chevron-right"></iron-icon>
           </button>
         </div>
       </div>
     </template>
   </template>
   <script src="chrome://history/history_toolbar.js"></script>
 </dom-module>