Support for element type: 'video' | 'canvas' and control of that element.

**Describe the solution you'd like**
If we could get control over the video or canvas element while the element is being shown, it could help us with several features like rendering AR, VR, Effects, Filters functionality.

**Describe alternatives you've considered**
It would provide us good support for development if MediaStream would be available, in that case, we can use several other features passing it through Web Tensorflow models to benefit better.