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

chrome/browser/resources/md_history/synced_device_manager.js

Index: chrome/browser/resources/md_history/synced_device_manager.js
diff --git a/chrome/browser/resources/md_history/synced_device_manager.js b/chrome/browser/resources/md_history/synced_device_manager.js
index b62a950c04c1232cec6655c9e982877e2ce3e447..5952e9bbc785cf4070dc31b4e2d974b9b36086c5 100644
--- a/chrome/browser/resources/md_history/synced_device_manager.js
+++ b/chrome/browser/resources/md_history/synced_device_manager.js
@@ -54,7 +54,9 @@ Polymer({
     fetchingSyncedTabs_: {
       type: Boolean,
       value: false,
-    }
+    },
+
+    hasSeenForeignData_: Boolean,
   },
 
   listeners: {
@@ -65,6 +67,9 @@ Polymer({
   attached: function() {
     // Update the sign in state.
     chrome.send('otherDevicesInitialized');
+    md_history.BrowserService.getInstance().recordHistogram(
+        SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.INITIALIZED,
+        SyncedTabsHistogram.LIMIT);
   },
 
   /**
@@ -124,15 +129,22 @@ Polymer({
 
   onOpenAllTap_: function() {
     var menu = assert(this.$.menu.getIfExists());
-    md_history.BrowserService.getInstance().openForeignSessionAllTabs(
+    var browserService = md_history.BrowserService.getInstance();
+    browserService.recordHistogram(
+        SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.OPEN_ALL,
+        SyncedTabsHistogram.LIMIT);
+    browserService.openForeignSessionAllTabs(
         menu.itemData);
     menu.closeMenu();
   },
 
   onDeleteSessionTap_: function() {
     var menu = assert(this.$.menu.getIfExists());
-    md_history.BrowserService.getInstance().deleteForeignSession(
-        menu.itemData);
+    var browserService = md_history.BrowserService.getInstance();
+    browserService.recordHistogram(
+        SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.HIDE_FOR_NOW,
+        SyncedTabsHistogram.LIMIT);
+    browserService.deleteForeignSession(menu.itemData);
     menu.closeMenu();
   },
 
@@ -198,6 +210,13 @@ Polymer({
     if (!sessionList)
       return;
 
+    if (sessionList.length > 0 && !this.hasSeenForeignData_) {
+      this.hasSeenForeignData_ = true;
+      md_history.BrowserService.getInstance().recordHistogram(
+        SYNCED_TABS_HISTOGRAM_NAME, SyncedTabsHistogram.HAS_FOREIGN_DATA,
+        SyncedTabsHistogram.LIMIT);
+    }
+
     // First, update any existing devices that have changed.
     var updateCount = Math.min(sessionList.length, this.syncedDevices_.length);
     for (var i = 0; i < updateCount; i++) {