GitLab

Replace some of the if-conditionals that check finch
params by DCHECKs since those experiments have finished.
Also, clean up the tests.

fieldtrial_testing_config.json has also been updated to
only reflect the parameters that we should be
experimenting with.

Change-Id: I1c3c2669c38dc7229b9c64b930b3342fa7843ca4
Bug: 513681
Reviewed-on: https://chromium-review.googlesource.com/1239695Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593698}