GitLab

This CL moves the functionality of
chrome/browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.*
into the TestUkmRecorder to provide the utility to other code that needs to
test URL keyed metrics.

NOTRY=true

Bug: 738921
Change-Id: I8c4e9101fc817e265415f4c45c174c5a1ef8ccc0
Reviewed-on: https://chromium-review.googlesource.com/565293
Commit-Queue: Dominic Battré <battre@chromium.org>
Reviewed-by: Bryan McQuade <bmcquade@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#485580}