Select correct ticker function during initialization (#725)

velocity.js

@@ -3582,7 +3582,7 @@
 		 devices to avoid wasting battery power on inactive tabs. */
 		/* Note: Tab focus detection doesn't work on older versions of IE, but that's okay since they don't support rAF to begin with. */
 		if (!Velocity.State.isMobile && document.hidden !== undefined) {
-			document.addEventListener("visibilitychange", function() {
+			var updateTicker = function() {
 				/* Reassign the rAF function (which the global tick() function uses) based on the tab's focus state. */
 				if (document.hidden) {
 					ticker = function(callback) {
@@ -3597,7 +3597,13 @@
 				} else {
 					ticker = window.requestAnimationFrame || rAFShim;
 				}
-			});
+			};
+
+			/* Page could be sitting in the background at this time (i.e. opened as new tab) so making sure we use correct ticker from the start */
+			updateTicker();
+
+			/* And then run check again every time visibility changes */
+			document.addEventListener("visibilitychange", updateTicker);
 		}
 
 		/************