title: ExtJS refresh after delete is successful
body: <p>I'm working with ExtJS, and when i delete a row in grid, i want it to refresh automatically. But so far without luck.
  This is my grid, and at the end is delete function</p>
  
  <pre><code>Ext.define('CrudExt.view.usuario.Grid',{
      extend: 'Ext.grid.Panel',
      title       : 'Lista brandova',
      itemId      : 'usuarioGrid',
      xtype       : 'usuariogrid',
      store       : 'Usuarios',
      initComponent: function(){
  
          this.columns = [
              { header: 'Sifra',  dataIndex: 'sifra' },
              { header: 'Brand', dataIndex: 'brand'}
          ];
  
          this.dockedItems = [
              {
                  xtype: 'toolbar',
                  dock: 'top',
                  items: [
                  {
                      xtype: 'button',
                      text: 'Dodaj',
                      iconCls: 'add',
                      action: 'add'
                  },
                  {
                      text    : 'Izbriši brand',
                      tooltip: 'Stisni za izbrisati brand.',
                      iconCls: 'delete',
                      itemId: 'delete',
                      scope: this,
                      handler: this.onDeleteClick
                  },
                  {
                      text: 'Izmjeni',
                      iconCls: 'edit',
                      action: 'edit'
                  }
              ]
          },
          {
              xtype: 'pagingtoolbar',
              store: 'Usuarios',
              dock: 'bottom',
              displayInfo: true
          }
          ];
  
          this.callParent(arguments);
  },
  
     onDeleteClick: function(grid){
      Ext.Msg.show({
           title:'Confirm Delete',
           msg: 'Deleting this document will delete ALL users associated with this group.&lt;br /&gt;ARE YOU SURE? Press "Yes" to delete.',
           buttons: Ext.Msg.YESNO,
           fn: processResult,
           icon: Ext.MessageBox.WARNING,
           scope: this
         });
      function processResult(buttonId){
          if (buttonId == 'yes'){
                var selection = this.getView().getSelectionModel().getSelection()[0];
                var rev = selection.get('sifra');
  
                Ext.Ajax.request
                ({
                   url : 'brand/delete/'+rev,
                   success   : function(response) 
                   {
  
                  }
                });
                //console.log(rev);
          } else {
                Ext.Msg.alert('The document has NOT been deleted');
          }
      };
  }
  
  });
  </code></pre>
  
  <p>what i did i tryed adding the following lines in success of the delte and none of them worked:</p>
  
  <pre><code>grid.getStore().load();
  store.reload();
  store.load();
  store.sync();
  this.getStore.load();
  Ext.getCmp('usuarioGrid').getView().refresh();
  grid.getView().refresh();
  </code></pre>