Remove Safe* math helper functions in gpu command buffer

The base::Check* function semantics are better.

BUG=905509
TEST=gpu_unittests
R=piman@chromium.org

Change-Id: I41093b6d168ce131f36739d6937b8518b0eb6cb2
Reviewed-on: https://chromium-review.googlesource.com/c/1408031
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624329}
14 files changed