MD History: Implement search functionality.

chrome/browser/resources/md_history/history_card.html

 <link rel="import" href="chrome://resources/polymer/v1_0/polymer/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/shadow.html">
 <link rel="import" href="chrome://history/history_item.html">
 
 <dom-module id="history-card">
   <template>
     <style>
       :host {
         @apply(--layout-center);
         @apply(--layout-vertical);
         padding: 0 24px 20px;
       }
 
+      :host([hidden]) {
+        display: none !important;
+      }
+
       #main-container {
         @apply(--shadow-elevation-2dp);
         background: #fff;
         border-radius: 2px;
         max-width: 960px;
         width: 100%;
       }
 
       #time-gap-separator {
         -webkit-border-start: 1px solid #888;
@@ skipping 13 matching lines @@
         font-weight: 500;
         height: 48px;
       }
 
       #history-item-list {
         padding: 8px 0;
       }
     </style>
 
     <div id="main-container">
-      <div id="date-accessed">[[historyDate]]</div>
+      <div id="date-accessed">
+        {{searchResultTitle_(historyItems.length, searchTerm, historyDate)}}

[tsergeant, 2016/02/04 02:28:49]

Can you rename searchResultTitle to cardTitle or something that doesn't
reference search (since it's not always a search)

[hsampson, 2016/02/08 04:40:22]

Done.

+      </div>
       <div id="history-item-list">
         <template is="dom-repeat" items="[[historyItems]]"

[tsergeant, 2016/02/04 02:28:49]

Make sure this is rebased correctly, so that bug doesn't crop up again

[hsampson, 2016/02/08 04:40:22]

Done.

             as="historyItem">
           <history-item time-accessed_="[[historyItem.dateTimeOfDay]]"
               website-title_="[[historyItem.title]]"
               website-domain_="[[historyItem.domain]]"
               website-url_="[[historyItem.url]]"
               starred="[[historyItem.starred]]"
               selected="{{historyItem.selected}}"
-              timestamp_="[[historyItem.time]]">
+              timestamp_="[[historyItem.time]]"
+              search-term="[[searchTerm]]">
           </history-item>
-          <template is="dom-if" if="[[needsTimeGap_(index, historyItem)]]">
+          <template is="dom-if" if="[[needsTimeGap_(index, historyItem, searchTerm)]]">
             <div id="time-gap-separator"></div>
           </template>
         </template>
       </div>
     </div>
   </template>
   <script src="chrome://history/history_card.js"></script>
 </dom-module>