remove base/containers/hash_tables*

We use only unordered_map/unordered_set from now.

Bug: 576864
Change-Id: Iedfa068bbe4c5934ce8fda8eaf77598e2d98a3a6
Reviewed-on: https://chromium-review.googlesource.com/c/1395861
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620718}
8 files changed