BUG=angleproject:2378
TEST=dEQP-GLES31.functional.debug.negative_coverage.get_error.texture.copytexsubimage2d_texture_internalformat

Change-Id: I4ad0ec6636c0312a3ecfeb47df3297e4bf399c35
Reviewed-on: https://chromium-review.googlesource.com/938328Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Yunchao He <yunchao.he@intel.com>