Polyfill non-functional when Chrome's experimental web platform features are enabled

[web-animations]

Polyfill non-functional when Chrome's experimental web platform features are enabled

[shans]

I think this is OK, given that you've got experimental features switched on - fallback to native isn't something we really need to support in this circumstance..

Fallback to native is already reasonably tricky supporting just 3 Chrome configurations (no API, pre m39 API, post m39 API) and will get a lot harder when Firefox native support ships. I'll look into why it isn't triggering in this configuration but I don't think it's worth complexifying the feature detection to support it.

[shans]

Looking into this further:

• fallback to native is happening. You can't tell by looking at Element.prototype.animate because web-animations-next hooks this. If you step through the code you can see that it's the native function being hooked.
• experimental web platform features exposes document.timeline and other bits and bobs. The polyfill's attempt at defining these is probably what is causing the demo to fail in this situation.

I'm leaning towards wontfix: if anyone disagrees, unlabel :)