Bug: angleproject:3188
Bug: angleproject:3797
Test: KHR-GLES2.texture_3d.framebuffer_texture.rgba8 (with patch from 3797)
Change-Id: Id44938504df00c3aba3fe733e7c71ad37ce1aab7
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1745838
Commit-Queue: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>