jQuery shaking on chromium workaround.js

/**
 * jQuery background position plugin
 * adapted to width recalculation
 * original by Alexander Farkas
 */
(function($) {

    Tween = jQuery.Tween;
    jQuery.Tween.prototype.run = function( percent ) {
            var eased,
                hooks = Tween.propHooks[ this.prop ];

            if ( this.options.duration ) {
                this.pos = eased = jQuery.easing[ this.easing ](
                    percent, this.options.duration * percent, 0, 1, this.options.duration
                );
            } else {
                this.pos = eased = percent;
            }
            positionProps = ['width', 'height', 'left', 'right', 'top', 'bottom', 'paddingLeft', 'paddingRight', 'paddingTop', 'paddingBottom', 
                'marginTop', 'marginLeft', 'marginBottom', 'marginRight'];
            if (jQuery.inArray(this.prop, positionProps) != -1)
                this.now = Math.round(( this.end - this.start ) * eased + this.start);
            else
                this.now = ( this.end - this.start ) * eased + this.start;

            if ( this.options.step ) {
                this.options.step.call( this.elem, this.now, this );
            }

            if ( hooks && hooks.set ) {
                hooks.set( this );
            } else {
                Tween.propHooks._default.set( this );
            }
            return this;
        };
})(jQuery);