Remove unused enums from enterprise_metrics.h

These enums haven't been used by any code for a while.

Also remove the corresponding dead histogram definitions.

BUG=chromium:690733
TEST=existing tests

Change-Id: I93b00807807e1869e5a7ab8daae277a07b6cf1e7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1425724
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Mattias Nissler <mnissler@chromium.org>
Reviewed-by: Pavol Marko <pmarko@chromium.org>
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641090}
4 files changed