Properly detect integer support on WebGL 2.0

Change-Id: Ib0461dd3be8e71537a76c87ca1d4a6501879381f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/279092
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
1 file changed