title: extjs tabpanel... stretch contents to fill screen vertically?
body: <p>In my extjs 6.0.0.640, in my panel, I have a tab panel.. inside tab panel I have 2 grids.  How do I stretch the grids vertically to fit inside the tab panel?  basically stretching the height to fill vertically?</p>
  
  <p>PROJECT CODE</p>
  
  <pre><code>Ext.define('ExtApplication4.view.performance.Performance', {
  extend: 'Ext.panel.Panel',
  
  xtype: 'app-performance',
  controller: 'performance',
  itemId: 'performanceItemId',
  
  requires: [
      'ExtApplication4.view.performance.PerformanceController',
      'ExtApplication4.util.GlobalVar',
      'Ext.chart.axis.Category',
      'Ext.chart.axis.Numeric',
      'Ext.chart.series.Line',
      'Ext.chart.series.Area'
  ],
  
  title: 'Performance',
  
  layout: {
      type: 'fit'
  },
  
  items: [
      {
          xtype: 'tabpanel',
          itemId: 'tabPanelId',
          activeTab: 0,
          //flex: 1,
          //height: '100%',
          items: [
              {
                  title: 'Portfolio Level',
                  //layout: {
                  //    type: 'vbox'
                  //},
                  items: [
                      {
                          xtype: 'grid',
                          title: 'Portfolio Level',
                          itemId: 'performancePortfolioLevelGridID',
                          bind: {
                              store: '{myPortfolioPerformanceStore}'
                          },
                          margin: '10px 0px 10px 0px',
                          ui: 'featuredpanel-framed',
                          cls: 'custom-gridPerformance',
                          //height: 500,
                          flex: 1,
                          width: 975,
                          collapsible: false,
                          listeners: {
                              itemClick: 'onAccountClick'
                          },
                          features: [{
                              ftype: 'summary',
                              dock: 'bottom'
                          }],
  columns: columns are here
  },
  {
                          title: 'Daily Portfolio Equity',
                          width: 975,
                          //height: 300,
                          flex: 1,
                          ui: 'featuredpanel-framed',
                          margin: '10px 0px 10px 0px',
                          xtype: 'chart',
                          theme: 'awesome2',
                          interactions: 'itemhighlight',
  }
  </code></pre>