BUG=swiftshader:15

Change-Id: I8e53f2fdb8208f8be0f4cdff3241b4a5efe9bc8a
Reviewed-on: https://chromium-review.googlesource.com/404352Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Jim Stichnoth <stichnot@chromium.org>