Make the User Timing API safe to use in MediaWiki

Allow JavaScript code to be annotated via the User Timing API without having to
repeatedly ensure that the API exists by declaring a no-op stub for browsers
that don't implement it. Do it in the startup module so we can use
performance.mark() early. Add an initial performance.mark() call as a use-case.

Task: T105389
Change-Id: Id686073da5baf3fcae36f296e6e50d648a543249

diff --git a/.jshintrc b/.jshintrc
index d72c31d..b84d276 100644 (file)
--- a/.jshintrc
+++ b/.jshintrc
@@ -22,6 +22,7 @@
                "mediaWiki": true,
                "JSON": true,
                "OO": true,
+               "performance": true,
                "jQuery": false,
                "QUnit": false,
                "sinon": false

diff --git a/resources/src/startup.js b/resources/src/startup.js
index 80cc7d9..5ee295b 100644 (file)
--- a/resources/src/startup.js
+++ b/resources/src/startup.js
@@ -6,6 +6,14 @@
 
 var mediaWikiLoadStart = ( new Date() ).getTime();
 
+if ( !window.performance ) {
+       window.performance = {};
+}
+if ( !performance.mark ) {
+       performance.mark = function () {};
+}
+performance.mark( 'mediaWikiStartUp' );
+
 /**
  * Returns false for Grade C supported browsers.
  *