function requestAnimationFrame(callback, element) {
		var i, requestAnimationFrameFunc = window.requestAnimationFrame, vendors = ['ms', 'moz', 'webkit'];

		function featurefill(callback) {
			window.setTimeout(callback, 0);
		}

		for (i = 0; i < vendors.length && !requestAnimationFrameFunc; i++) {
			requestAnimationFrameFunc = window[vendors[i] + 'RequestAnimationFrame'];
		}

		if (!requestAnimationFrameFunc) {
			requestAnimationFrameFunc = featurefill;
		}

		requestAnimationFrameFunc(callback, element);
	}
Utility class for working with delayed actions like setTimeout.

@class tinymce.util.Delay