window.performance.now()

  const s = window.performance.now()

  this.$refs.table.toggleRowSelection(row)

   setTimeout(() => {
     this.renderTime = (window.performance.now() - s).toFixed(2) + 'ms'
   })

console.time方法与console.timeEnd方法

console.time('small loop');
for (var i = 0; i < 100000; i++) {
    ;
}
console.timeEnd('small loop');

console.time(1);
setTimeout(function(){
    console.timeEnd(1);
}, 16.7);

Benchmark.js

var suite = new Benchmark.Suite;

// add tests
suite.add('RegExp#test', function() {
  /o/.test('Hello World!');
})
.add('String#indexOf', function() {
  'Hello World!'.indexOf('o') > -1;
})
// add listeners
.on('cycle', function(event) {
  console.log(String(event.target));
})
.on('complete', function() {
  console.log('Fastest is ' + this.filter('fastest').map('name'));
})
// run async
.run({ 'async': true });

// logs:
// => RegExp#test x 4,161,532 +-0.99% (59 cycles)
// => String#indexOf x 6,139,623 +-1.00% (131 cycles)
// => Fastest is String#indexOf