Google Canary - on Macbook Air OSX 10.9.4 is giving error

Question

Is this a BUG in Mac or Canary?

I need to use the screen-capture via Google Canary, which was working before in past old versions.

But since they release Canary

Answer 1

Firefox also now has screen/window/etc capture. For now, for similar reasons to Chrome, we've put access to the feature behind a whitelist (though an extension could extend the whitelist as well; we haven't prototyped that yet).

See http://mozilla.github.io/webrtc-landing/gum_test.html (In Firefox 33 or later - currently that's Beta; no attempt to polyfill was done there as it's an internal testing page).