Move //components/metrics/compression_utils into standalone component
This file is used by code in //chrome/browser/metrics/variations that itself is
slated for componentization. As //components/metrics depends on
//components/variations, the code in question would not be able to be
componentized into //components/variations. To enable that, this CL moves
compression_utils* to a standalone lower-level component.
BUG=516662, 515695
TBR=agl
Review URL: https://codereview.chromium.org/
1304563003
Cr-Commit-Position: refs/heads/master@{#345309}