MD Bookmarks: Add a metric to measure load-time performance

chrome/browser/resources/md_bookmarks/app.js

Index: chrome/browser/resources/md_bookmarks/app.js
diff --git a/chrome/browser/resources/md_bookmarks/app.js b/chrome/browser/resources/md_bookmarks/app.js
index 7bc97e96699538742d8f955398107c7c102ce268..50c783cd7083c13d01d920ba92ed096dcd117853 100644
--- a/chrome/browser/resources/md_bookmarks/app.js
+++ b/chrome/browser/resources/md_bookmarks/app.js
@@ -57,6 +57,12 @@ Polymer({
       bookmarks.Store.getInstance().init(initialState);
       bookmarks.ApiListener.init();
 
+      setTimeout(function() {
+        chrome.metricsPrivate.recordTime(
+            'BookmarkManager.ResultsRenderedTime',
+            Math.floor(window.performance.now()));
+      });
+
     }.bind(this));
 
     this.boundUpdateSidebarWidth_ = this.updateSidebarWidth_.bind(this);