Remove RTT and throughput estimates observer from UI NQE class

These are not being used, and makes it easier to transition NQE
(Network Quality Estimator) observers for network servicification.

Change-Id: I1f22a66e134a2cd1af89ac4b7bd274091934dd51
Bug: 819244
Reviewed-on: https://chromium-review.googlesource.com/1132685
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574241}
5 files changed