Shifting these fields was breaking the build in Linux GCC.

BUG=angle:690

Change-Id: I34286753f7ab636900f25f880187dbb297e9c040
Reviewed-on: https://chromium-review.googlesource.com/206632Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>