remove self.performance.now support from header.js, it is no longer needed.

utils/npm/header.js

@@ -1,34 +1 @@
-var self = self || {};
-
-// High-resulution counter: emulate window.performance.now() for THREE.CLOCK
-if( self.performance === undefined ) {
-
-	self.performance = {};
-
-}
-
-if( self.performance.now === undefined ) {
-
-	// check if we are in a Node.js environment
-	if( ( process !== undefined ) && ( process.hrtime !== undefined ) ) {
-
-		self.performance.now = function () {
-
-			var time = process.hrtime();
-			return ( time[0] + time[1] / 1e9 ) * 1000;
-
-		};
-
-	}
-	// if not Node.js revert to using the Date class
-	else {
-
-		self.performance.now = function() {
-
-			return new Date().getTime();
-
-		};
-
-	}
-
-}
+var self = self || {};