Caused failures in the WebglConformance.conformance_textures_misc_copy_tex_image_2d_formats test on the ATI FYI waterfall bot.
This reverts commit 61f51dc1.

Change-Id: Iddea03d53ae2a9b639e36931f01c1e889e550af4
Reviewed-on: https://chromium-review.googlesource.com/294262Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>