Audit size_t: odds and ends in gpu/command_buffer/client

Mostly just replacing size_t (and unsigned int) to uint32_t as
appropriate.

Bug: 905509
Change-Id: Ie74917ae87e989c461542f3de7651951aabdbfbb
Reviewed-on: https://chromium-review.googlesource.com/c/1401850
Commit-Queue: Antoine Labour <piman@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621294}
5 files changed