security: remove getBuiltin() and depending functions

[kewde]

In the spirit of #644

getBuiltin() allows you to get any arbitrary electron module, such as app.

Page 9 - app = ipcRenderer.sendSync('ELECTRON_BROWSER_GET_BUILTIN', 'app') https://www.blackhat.com/docs/us-17/thursday/us-17-Carettoni-Electronegativity-A-Study-Of-Electron-Security-wp.pdf

[kewde]

I haven't tried it out, but try getting the 'shell' module of electron.

Just tested, good way to execute code from within the sandbox because it goes through IPC. Meh, I never really like chrome.remote, I always delete the reference in my app.

[diracdeltas]

thanks @kewde . i think this is obsoleted by https://github.com/brave/muon/commit/487188c3e0777feefe2c8a23dfc559f887873083 though? @bridiver

[kewde]

@diracdeltas that does the job as well.