Is window.performance enough to enable adaptive quality scaling or should we have a browser level function?

[Utopiah]

Should the browser provide an interface to reduce/increase performance requests on different aspects (e..g level of precision in physics, foveated rendering, level of detail thresholds) relying on user defined callbacks?

What are the security concerns?

PS: there is already window.performance, window.requestIdleCallback (poor support but on-going discussion in the specs), window.requestAnimationFrame and VRDisplay.requestAnimationFrame (then eventually VRSession.requestFrame) or at a higher level https://github.com/mrdoob/stats.js/ but could be generalized to more than WebVR anyway.

[Utopiah]

@tbalouet glTF progressive streaming / LoD cf KhronosGroup/glTF#1045 would be also very useful here