History: Add load-time metric for non-MD and MD History WebUI

chrome/browser/resources/history/history.js

Index: chrome/browser/resources/history/history.js
diff --git a/chrome/browser/resources/history/history.js b/chrome/browser/resources/history/history.js
index 7643b8fd336866b834cfcf4ee793251c74102bde..5ca33c68c215669b61205f32eb35223be17c88a2 100644
--- a/chrome/browser/resources/history/history.js
+++ b/chrome/browser/resources/history/history.js
@@ -939,6 +939,7 @@ function HistoryView(model) {
   this.model_ = model;
   this.pageIndex_ = 0;
   this.lastDisplayed_ = [];
+  this.hasRenderedResults_ = false;
 
   this.model_.setView(this);
 
@@ -1122,6 +1123,15 @@ HistoryView.prototype.onModelReady = function(doneLoading) {
     var isSearch = this.model_.getSearchText().length > 0;
     $('search-field').hidden = !(hasResults || isSearch);
   }
+
+  if (!this.hasRenderedResults_) {
+    this.hasRenderedResults_ = true;
+    requestAnimationFrame(function() {
+      chrome.send(
+          'metricsHandler:recordTime',
+          ['History.ResultsRenderedTime', window.performance.now()]);
+    });
+  }
 };
 
 /**