title: afterrender not working for combobox when used in grid in EXTJS
body: <p>This is my code for combo box inside grid:</p>
  
  <pre><code>{
      header: 'FSCS',
      dataIndex: 'acntOvrrideTypeCd',
      flex: 1,
      renderer: function(val, metaData, record, rowIndex, colIndex) {
          var id = Ext.id();
          var store = new Ext.data.Store({
              fields: ['code', 'description'],
              data: [{
                  "code": "",
                  "description": ""
              }, {
                  "code": "E",
                  "description": "E"
              }, {
                  "code": "D",
                  "description": "D"
              }, {
                  "code": "S",
                  "description": "S"
              }]
          });
  
          Ext.Function.defer(
              (function() {
                  var cb = Ext.create('Ext.form.ComboBox', {
                      id: 'acntOvrrideTypeCd-' + rowIndex,
                      queryMode: 'local',
                      renderTo: id,
                      store: store,
                      forceSelection: true,
                      triggerAction: 'all',
                      lazyRender: true,
                      size: 5,
                      valueField: 'code',
                      displayField: 'description',
                      value: val
                      //listeners:{
                      //    scope: this,
                      //    'select': Ext.getCmp('amlFscsForm').controller.amlShow(rowIndex)
                      //}
  
                  });
                  cb.on(afterrender, function() {
                      console.log("------- box---" + rowIndex);
                      Ext.getCmp('amlFscsForm').controller.amlShow(rowIndex);
                  });
              }), 0.25);
  
          console.log("i----------" + id);
          return (Ext.String.format('&lt;div id="{0}"&gt;&lt;/div&gt;', id));
      }
  }
  </code></pre>
  
  <p>'afterrender' event is not fired. I need to enable or disable component after its rendered.</p>
  
  <p>Can anyone help?</p>