Hide scrollbars only when updated manually.

Resolve #283.

src/js/plugin/update.js

@@ -3,7 +3,8 @@
  */
 'use strict';
 
-var destroy = require('./destroy')
+var d = require('../lib/dom')
+  , destroy = require('./destroy')
   , initialize = require('./initialize')
   , instances = require('./instances')
   , updateGeometry = require('./update-geometry');
@@ -17,6 +18,13 @@ module.exports = function (element) {
     destroy(element);
     initialize(element);
   } else {
+    // Hide scrollbars not to affect scrollWidth and scrollHeight
+    d.css(i.scrollbarXRail, 'display', 'none');
+    d.css(i.scrollbarYRail, 'display', 'none');
+
     updateGeometry(element);
+
+    d.css(i.scrollbarXRail, 'display', 'block');
+    d.css(i.scrollbarYRail, 'display', 'block');
   }
 };