Fix issue with copying to a texture from a HTMLVideoElement

[ggetz]

Description

A HTMLVideoElement has additional videoHeight and videoWidth properties. These are the intrinsic dimensions. If we rely on the height and width values, we can get sub optimal values, and – as in the case of the reported bug – sometimes 0 values, which can break the WebGL operation entirely.

While I was in that code, I also opted to use naturalHeight and naturalWidth for HTMLImageElement, as those the intrinsic, not scaled, dimensions.

Issue number and link

Fixes #12219

Testing plan

1. Visit the Video.html Sandcastle example
2. Ensure the video is running on the sphere
3. Open the development console and ensure no WebGL errors are reported

Author checklist

• I have submitted a Contributor License Agreement
• I have added my name to CONTRIBUTORS.md
• I have updated CHANGES.md with a short summary of my change
• I have added or updated unit tests to ensure consistent code coverage
• I have updated the inline documentation, and included code examples where relevant
• I have performed a self-review of my code

[github-actions]

Thank you for the pull request, @ggetz!

✅ We can confirm we have a CLA on file for you.

[ggetz]

@jjspace Could you please review this fix for tomorrow's release?

[jjspace]

Can confirm the sandcastle is now working again. Happy to see it was a small fix. Just had one small comment

[ggetz]

Thanks @jjspace! Updated!

[jjspace]

LGTM!