Policies based on device criteria

[robinglen]

I was looking at [https://github.com/WICG/feature-policy/blob/gh-pages/policies/animations.md](animation policy) and it made me think about activating policies based on certain device criteria.

For example if battery is low or on energy saving mode toggle an animation policy which would disable animations just jumping them to the last frame.

You can handcraft this but just wondering if its something the platform could help out with?