resourceloader: Use Date.now() for mw.now() instead of '+new Date'

Now that ES5 is required, use Date.now(). Performs better by not
requiring object construction.

Bug: T160953
Change-Id: Ifea106a325659c2024f40e77ff016db9dc8a55fb

diff --git a/resources/src/startup.js b/resources/src/startup.js
index e0cdc4d..e8ccba0 100644 (file)
--- a/resources/src/startup.js
+++ b/resources/src/startup.js
@@ -15,7 +15,7 @@ var mwPerformance = ( window.performance && performance.mark ) ? performance : {
                        navStart = perf && perf.timing && perf.timing.navigationStart;
                return navStart && typeof perf.now === 'function' ?
                        function () { return navStart + perf.now(); } :
-                       function () { return +new Date(); };
+                       function () { return Date.now(); };
        }() ),
        // eslint-disable-next-line no-unused-vars
        mediaWikiLoadStart = mwNow();