Explicitly disabled tests:
- DifferentStencilMasksTest.DrawWithDifferentMask
- PointSpritesTest.PointSizeAboveMaxIsClamped
- WebGL2ReadOutsideFramebufferTest.CopyTexSubImage3D

Bug: angleproject:2634
Change-Id: I76ab450c06d0e1be1e7469a8b9c6497684c3ca54
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1906607
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>