use requestAnimationFrame for window scroll event

@@ -133,7 +133,7 @@ function search() {
     });
 }
 
-$('.maybe-like p').on('touchstart', function (e) {
+$('.maybe-like p').on('touchstart', function(e) {
     search();
 });
 

@@ -68,28 +68,33 @@ $channelLink.on('touchstart', function() {
         borderColor: '#fff'
     });
 });
-var updateLayerPosition = (function() {
-   var init = false;
-   return function() {
-     var winHeight = window.innerHeight;
-     var bodyHeight = $doc.height();
-     var scrollTopPosition = $win.scrollTop();
-     var layerHeight = $appFloatLayer.height();
-     var layerPaddingTop = parseInt($appFloatLayer.css('padding-top'));
-     var layerPaddingBottom = parseInt($appFloatLayer.css('padding-bottom'));
-     var newPosition;
-     if(init){
-       newPosition = bodyHeight - winHeight- scrollTopPosition;
-     }else{
-       init = true;
-       newPosition = bodyHeight - winHeight - scrollTopPosition + layerHeight + layerPaddingTop + layerPaddingBottom;
-     }
-     $appFloatLayer.css({
-       'position': 'relative',
-       'bottom': newPosition + 'px'
-     });
-   };
-})();
+
+function updateLayerPosition() {
+    var init = false;
+
+    return function() {
+        var winHeight = window.innerHeight;
+        var bodyHeight = $doc.height();
+        var scrollTopPosition = $win.scrollTop();
+        var layerHeight = $appFloatLayer.height();
+        var layerPaddingTop = parseInt($appFloatLayer.css('padding-top'));
+        var layerPaddingBottom = parseInt($appFloatLayer.css('padding-bottom'));
+        var newPosition;
+
+        if (init) {
+            newPosition = bodyHeight - winHeight - scrollTopPosition;
+        } else {
+            init = true;
+            newPosition = bodyHeight - winHeight - scrollTopPosition +
+                layerHeight + layerPaddingTop + layerPaddingBottom;
+        }
+
+        $appFloatLayer.css({
+            position: 'relative',
+            bottom: newPosition + 'px'
+        });
+    };
+}
 
 $(window).scroll(function() {
     window.requestAnimationFrame(updateLayerPosition);

@@ -347,7 +347,6 @@ $listNav.on('touchend touchcancel', function(e) {
             search();
         }
     }
-    
     e.stopPropagation();
 });
 

@@ -72,7 +72,7 @@ $(window).scroll(function() {
 
 hotrank(page, sort, id, notab);
 hotnav = new Hammer(document.getElementById('hotRank'));
-hotnav.on('tap', function (e) {
+hotnav.on('tap', function(e) {
     var ev = ev || window.event;
     var target = ev.target || ev.srcElement;