[MD History] Copy stats from the old history page.

chrome/browser/resources/md_history/synced_device_card.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: 'history-synced-device-card',
 
   properties: {
     // Name of the synced device.
     device: String,
@@ skipping 29 matching lines @@
   },
 
   /**
    * Open a single synced tab. Listens to 'click' rather than 'tap'
    * to determine what modifier keys were pressed.
    * @param {DomRepeatClickEvent} e
    * @private
    */
   openTab_: function(e) {
     var tab = /** @type {ForeignSessionTab} */(e.model.tab);
-    md_history.BrowserService.getInstance().openForeignSessionTab(
+    var browserService = md_history.BrowserService.getInstance();
+    browserService.recordHistogram(
+        SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.LINK_CLICKED,
+        SyncedTabsHistogram.LIMIT);
+    browserService.openForeignSessionTab(
         this.sessionTag, tab.windowId, tab.sessionId, e);
     e.preventDefault();
   },
 
   /**
    * Toggles the dropdown display of synced tabs for each device card.
    */
   toggleTabCard: function() {
+    var histogramValue = this.$.collapse.opened ?
+        SyncedTabsHistogram.COLLAPSE_SESSION :
+        SyncedTabsHistogram.EXPAND_SESSION;
+
+    md_history.BrowserService.getInstance().recordHistogram(
+        SYNCED_TABS_HISTOGRAM_NAME, histogramValue,
+        SyncedTabsHistogram.LIMIT);
+
     this.$.collapse.toggle();
     this.$['dropdown-indicator'].icon =
         this.$.collapse.opened ? 'cr:expand-less' : 'cr:expand-more';
   },
 
   /**
    * When the synced tab information is set, the icon associated with the tab
    * website is also set.
    * @private
    */
@@ skipping 27 matching lines @@
    * @private
    */
   onMenuButtonTap_: function(e) {
     this.fire('toggle-menu', {
       target: Polymer.dom(e).localTarget,
       tag: this.sessionTag
     });
     e.stopPropagation();  // Prevent iron-collapse.
   },
 });