[MD History] Disable clicks in the date header of cards.

chrome/browser/resources/md_history/history_item.html

 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/cr/ui/focus_row.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/polymer/v1_0/paper-styles/shadow.html">
 <link rel="import" href="chrome://resources/html/icon.html">
 <link rel="import" href="chrome://resources/html/util.html">
 <link rel="import" href="chrome://history/browser_service.html">
 <link rel="import" href="chrome://history/constants.html">
 <link rel="import" href="chrome://history/searched_label.html">
@@ skipping 189 matching lines @@
 
       :host([is-card-start][is-card-end]) #background {
         border-radius: 2px;
       }
     </style>
 
     <div id="main-container">
       <div id="background-clip">
         <div id="background"></div>
       </div>
-      <div id="date-accessed" class="card-title">
+      <div id="date-accessed" class="card-title"
+          on-mousedown="onTitleMousedown_">

[Dan Beam, 2016/10/13 17:40:24]

can we just do pointer-events: none instead?  basically the same

[calamity, 2016/10/14 12:26:25]

Done.

         [[cardTitle_(numberOfItems, item.dateRelativeDay, searchTerm)]]
       </div>
       <div id="item-container">
         <button is="paper-icon-button-light" id="checkbox"
             on-mousedown="onCheckboxMousedown_"
             on-click="onCheckboxSelected_"
             disabled="[[selectionNotAllowed_()]]"
             role="checkbox"
             aria-checked$="[[getAriaChecked_(selected)]]"
             aria-label$="[[getEntrySummary_(item)]]">
@@ skipping 24 matching lines @@
           <div></div>
           <div></div>
           <div></div>
         </button>
       </div>
       <div id="time-gap-separator" hidden="[[!hasTimeGap]]"></div>
     </div>
   </template>
   <script src="chrome://history/history_item.js"></script>
 </dom-module>