code: function() {
              var animateWithClass = this.animateClearButton && this.animateWithCss3;
              this.clearButtonEl = this.textField.bodyEl.createChild({
                  tag: 'div',
                  cls: this.clearButtonCls
              });
              if(this.animateClearButton) {
                  this.animateWithCss3 = this.supportsCssTransition(this.clearButtonEl);
              }
              if(this.animateWithCss3) {
                  this.clearButtonEl.addCls(this.clearButtonCls + '-off');
              }
              else {
                  this.clearButtonEl.setStyle('visibility', 'hidden');
              }
          }
docs: Creates the Element and DOM for the clear button