GitLab

Use network quality tracker instead of network quality estimator (NQE)
to obtain network quality when attaching network quality
client hints for main frame resources.

Network quality tracker can provide network service when network
service is enabled as well as when network service is disabled.

Change-Id: Iafa641ecb487bb00aecc0d3f1a18cfcdabba3de8
Bug: 819244
Reviewed-on: https://chromium-review.googlesource.com/1170568Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582296}