BUG=swiftshader:15

Change-Id: Ib89d628c85696c20a249b8810cd357a292d10402
Reviewed-on: https://chromium-review.googlesource.com/405293Reviewed-by: Jim Stichnoth <stichnot@chromium.org>
Tested-by: Nicolas Capens <nicolascapens@google.com>