Notify user when site try to use WebGL, WebRTC, Webassembly when they are disabled.

[Rexadev]

chrome://settings/content/javascript-jit
chrome://settings/content/webgl
chrome://settings/content/webrtc

It is hard to know that is breaking the site or worse what I am missing from site.
NoScript Extension has option to keep WebGL disabled till websites asks to use it and asks user if it whats to enable it for a site

@macchrome

[uazo]

for javascript-jit nothing can be done

with regard to webgl and webrtc, websites already have everything they need to understand via javascript whether to inform the user, but since the standard seems to be what chrome does, developers don't care.

In any case, I confirm that I am willing to develop something about it.

[uazo]

related #323