use perf_hooks

Summary:
We were using `window.performance` to measure performance. This was because the equivalent node.js API `perf_hooks` wasn't available in the electron version we were using back then.
However, `perf_hooks` has landed in electron meanwhile, so I am moving to this API, as it works for the headless version and jest tests, too.

This allows us to delete the babel transform that was used for node-based tests, where the browser API was replaced with the node API

Reviewed By: jknoxville

Differential Revision: D13860133

fbshipit-source-id: cf1395004fac046dd55751ff465af494173b2cbf

static/transforms/__tests__/electron-stubs.node.js

@@ -6,8 +6,6 @@
  */
 
 import {transform} from '@babel/core';
-import generate from '@babel/generator';
-
 import electronStubs from '../electron-stubs';
 
 const babelOptions = {
@@ -23,14 +21,3 @@ test('transform electron requires to inlined stubs', () => {
   expect(body.type).toBe('ExpressionStatement');
   expect(body.expression.properties.map(p => p.key.name)).toContain('remote');
 });
-
-test('transform performance calls to requires', () => {
-  for (const method of ['mark', 'measure']) {
-    const src = `performance.${method}('something')`;
-    const transformed = transform(src, babelOptions).ast;
-    const {code} = generate(transformed);
-    expect(code).toBe(
-      `require('perf_hooks').performance.${method}('something');`,
-    );
-  }
-});