[Bug] stealth evasion `navigator.webdriver` needs to be updated following the Chrome v89 release

The behavior of the navigator.webdriver property has been changed in commit bfe0108 of Chrome like this:

	before	after
headful	undefined	false
headless	true	true

Therefore the navigator.webdriver evasion here shall be updated accordingly.

This specific commit bfe0108 has been part of Chrome since major version 89, and recently the stable channel of release has advanced to major version 89, making the fix seemingly more important than before.

[starrify]

This line will just fail/do nothing in chrome >= 88.0.4291.0 (as the prop is immutable)

Hmm sorry but I might have got other ideas…

$ cat test.js 
// puppeteer@6.0.0 -- bundled Chromium 89.0.4389.0
// puppeteer-extra@3.1.17
// puppeteer-extra-plugin-stealth@2.7.5
(async () => {
  const { addExtra } = require('puppeteer-extra');
  const puppeteer = addExtra(require('puppeteer'));
  if (process.env.TEST_EVASION == 'true') {
    puppeteer.use(
      require('puppeteer-extra-plugin-stealth/evasions/navigator.webdriver')()
    );
  }
  const browser = await puppeteer.launch({
    headless: process.env.TEST_HEADLESS == 'true',
  })
  const page = await browser.newPage();
  const result = await page.evaluate(() => navigator.webdriver);
  console.log(result);
  await page.close();
  await browser.close();
})();

$ TEST_EVASION=false TEST_HEADLESS=true node test.js 
true

$ TEST_EVASION=false TEST_HEADLESS=false node test.js 
true

$ TEST_EVASION=true TEST_HEADLESS=true node test.js 
undefined

$ TEST_EVASION=true TEST_HEADLESS=false node test.js 
undefined

[berstend]

I see that potentially erroneous since that deletes the property unconditionally.

Ah gotcha 😃 This line will just fail/do nothing in chrome >= 88.0.4291.0 (as the prop is immutable), this could be added to the comment to make that clear and avoid confusion. 😃

Plus at least the unit tests still expect an undefined value unconditionally

Oh, good catch - this would make CI fail in the future once we use more recent chrome versions