Javascript Videojs removeChild方法不工作

我正在为

videojs

编写一个新插件。我对if声明有异议：

if (getCTime == 5 && c == true) {
      this.removeChild(createDiv);
}

5秒后无法移除div元素。我该怎么办

代码：

(function() {
    'use strict';

    //Create Component

    videojs.containerDiv = videojs.Component.extend({ 
        init: function(player, options) {
            videojs.Component.call(this, player, options);
        }
    });

    // get current time and create new element
    videojs.containerDiv.prototype.timeUpdate = function(player, options) {
        var c = false;
        this.player_.on('timeupdate', function() {

            var getCTime = Math.floor(this.cache_.currentTime);
            var createDiv = new videojs.containerDiv(this, options);

            // In 2 seconds are show ads
            if (getCTime == 2 && c == false) {

                // Create new div for ads

                this.addChild(createDiv);

                //Close ads
                this.one(createDiv.newDivClose_,'click', function() {
                    this.removeChild(createDiv);
                });

                c = true;
            }

            if (getCTime == 5 && c == true) {
               this.removeChild(createDiv);
            }
        });
    }

    videojs.containerDiv.prototype.createEl = function() {

        var newDiv = videojs.createEl('div', {
            className: 'vjs-new-div'
        });

        var newDivInside = videojs.createEl('div', {
            className: 'vjs-new-div-inside'
        });        

        var newDivClose = videojs.createEl('div', {
            className: 'vjs-btn-close',
            innerHTML: 'x'
        });

        this.newDivClose_ = newDivClose;

        newDiv.appendChild(this.newDivClose_);

        this.contentEl_ = newDivInside;

        this.contentEl_.innerHTML = this.innerHTML();
        newDiv.appendChild(this.contentEl_);

        return newDiv;
    };

    videojs.containerDiv.prototype.innerHTML = function() {
        this.textAds = "Hello World";
        return this.textAds;
    }

    var pluginFn = function(options) {
        var myComponent =  new videojs.containerDiv(this, options);
        myComponent.timeUpdate(this, options);
    };


    videojs.plugin( 'myPlugin', pluginFn );
})();