Bug(Camera): On camera zoom camera aspect has wrong values when Aframe is embeded #HighPriority

Description:
I'm a développer working currently with Aframe library.
I have to handle zoom and fov with an Aframe camera.
My problem is when i use Aframe camera and when i set the zoom, the display aspect is strongly wrong.
I have see a PR this morning talking about that, this is a bug on camera, because when the developper set the camera aspect it's strongly wrong to take window.heigh and window.width.
It's also wrong when set camera aspect with data.aspect and not registring it on schema because it makes people able to pass variables into data.aspect but with getting a warn.
My opinion is that data.aspect should be registred in schema and that aspect has to be dynamicly set when embeded.
You can test it, by pull Aframe v0.4.0 and by changing camera fov and zoom.
I think this should be quickly fixed because it's break some feature like zoom.

• A-Frame Version: v0.4.0
• Platform/Device: All Platform
• Reproducible Code Snippet or Demo URL [highly encouraged]:

Reproduce the reported behavior with A-Frame v0.4.0 by changing the camera FOV and zoom in an embedded scene. Compare the resulting camera aspect with the expected embedded display dimensions, and verify that the aspect configuration is registered and updates correctly when the issue is fixed.