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

chrome/browser/resources/md_history/synced_device_card.js

Index: chrome/browser/resources/md_history/synced_device_card.js
diff --git a/chrome/browser/resources/md_history/synced_device_card.js b/chrome/browser/resources/md_history/synced_device_card.js
index 8090df8ae3b0a0587737661eda5022417c8b734b..20a9151524b6ea025ddd058994fc8847976967f6 100644
--- a/chrome/browser/resources/md_history/synced_device_card.js
+++ b/chrome/browser/resources/md_history/synced_device_card.js
@@ -47,7 +47,11 @@ Polymer({
    */
   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();
   },
@@ -56,6 +60,14 @@ Polymer({
    * 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';