[MD Bookmarks] Deselect items when clicking outside the bookmark card.

chrome/browser/resources/md_bookmarks/item.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 Polymer({
   is: 'bookmarks-item',
 
   behaviors: [
     bookmarks.StoreClient,
   ],
@@ skipping 71 matching lines @@
     this.isFolder_ = !(this.item_.url);
   },
 
   /**
    * @param {Event} e
    * @private
    */
   onClick_: function(e) {
     this.dispatch(bookmarks.actions.selectItem(
         this.itemId, e.ctrlKey, e.shiftKey, this.getState()));
+    e.stopPropagation();
   },
 
   /**
    * @param {Event} e
    * @private
    */
   onDblClick_: function(e) {
     if (!this.item_.url)
       this.dispatch(bookmarks.actions.selectFolder(this.item_.id));
     else
       chrome.tabs.create({url: this.item_.url});
   },
 
   /**
    * @param {string} url
    * @private
    */
   updateFavicon_: function(url) {
     this.$.icon.style.backgroundImage = cr.icon.getFavicon(url);
   },
 });