metamask-extension/app/scripts/disable-console.js

// Disable console.log in contentscript to prevent SES/lockdown logging to external page
// eslint-disable-next-line import/unambiguous
if (
  !(typeof process !== 'undefined' && process.env.METAMASK_DEBUG) &&
  typeof console !== undefined
) {
  console.log = noop
  console.info = noop
}

function noop() {
  return undefined
}