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

chrome/browser/resources/history/externs.js

Index: chrome/browser/resources/history/externs.js
diff --git a/chrome/browser/resources/history/externs.js b/chrome/browser/resources/history/externs.js
index 123c2502abc39e8bbf3ba359b83066e255b22ef8..9a07638b194a2aa397107c37eaea8eea69691486 100644
--- a/chrome/browser/resources/history/externs.js
+++ b/chrome/browser/resources/history/externs.js
@@ -75,3 +75,12 @@ var ForeignSessionWindow;
  *            windows: Array<ForeignSessionWindow>}}
  */
 var ForeignSession;
+
+// Other externs required to compile history:
+
+var performance = {};
+
+/**
+ * @return {number}
+ */
+performance.now = function() {};

[Dan Beam, 2016/08/03 21:05:17]

i haz a sad
https://github.com/google/closure-compiler/blob/8a468ed4abb4ececc5f24928aac2f...

[tsergeant, 2016/08/03 22:53:56]

Is there any particular reason why these aren't pulled into Chrome?

[Dan Beam, 2016/08/04 03:51:33]

it should be. have you tried window.performance.now?

[tsergeant, 2016/08/04 03:59:06]

Ah, that works 🙌

(that doesn't show up in a code search, which was why I was confused)