function injectScript (scriptName, cb) {
  const src = `
    (function() {
      var script = document.constructor.prototype.createElement.call(document, 'script');
      script.src = "${scriptName}";
      document.documentElement.appendChild(script);
      script.parentNode.removeChild(script);
    })()
  `
  chrome.devtools.inspectedWindow.eval(src, function (res, err) {
    if (err) {
      console.log(err)
    }
    cb()
  })
}
function injectScript (scriptName, cb) {
  const src = `
    (function() {
      var script = document.constructor.prototype.createElement.call(document, 'script');
      script.src = "${scriptName}";
      document.documentElement.appendChild(script);
      script.parentNode.removeChild(script);
    })()
  `
  chrome.devtools.inspectedWindow.eval(src, function (res, err) {
    if (err) {
      console.log(err)
    }
    cb()
  })
}
function injectScript ( scriptName , cb ) { const src = ` ${ scriptName } ` chrome . devtools . inspectedWindow . eval ( src , function ( res , err ) { if ( err ) { console . log ( err ) } cb ( ) } ) }
Inject a globally evaluated script, in the same context with the actual
user app.

@param {String} scriptName
@param {Function} cb
Inject a globally evaluated script in the same context with the actual user app .
Inject a script into the page