Steps to reproduce the problem: 1. write the following in a console 2. requestAnimationFrame(function(){'use strict';alert(this)}); 3. see that `window` is alerted instead of `undefined` What is the expected behavior? function should be invoked with undefined context to fullfill both sloppy and strict expectations What went wrong? suddenly, the wild global context appears ... Did this work before? No Chrome version: 39.0.2149.0 Channel: canary OS Version: OS X 10.8.5 Flash Version: Shockwave Flash 15.0 r0 every single Chrome I could test with requestAnimationFrame out of its prefixed version.
See also: https://code.google.com/p/chromium/issues/detail?id=411959
>3. see that `window` is alerted instead of `undefined` Not quite. What's alerted is the function that was passed to requestAnimationFrame.
Boris is right, it was a copy and paste from Chromium, apologies.
*** This bug has been marked as a duplicate of bug 126680 ***