Those parameters aren't optional in the current spec.
The test element-array-buffer-delete-recreate.html now fails because we don't
actually implement gl.getParameter(gl.CURRENT_PROGRAM).
This fixes a regression caused by the glutin update.
We now are creating EGL contexts in Linux Wayland, instead of X context, so the
GLContextFactory assumption of one GL back-end per platform is broken.
This just works around it, for now, but in general I think not relying on
available WebGL state is a good thing, and we do that already for WebVR anyway.
Set the expected result of the test `tex-input-validation.html` to CRASH, since
that is caused by unrelated problems. The test was previously not executing
completely, because it stopped when it didn't find the implementation of
getTexParameter.
Add support for filtering WebGL extensions based on WebGL version
<!-- Please describe your changes on the following line: -->
Add support for filtering WebGL extensions based on WebGL version
---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).
<!-- Either: -->
- [x] There are tests for these changes OR
- [ ] These changes do not require tests because _____
<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->
<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->
<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/19040)
<!-- Reviewable:end -->
