Revert "NQE servicification of data saver proxy"

This reverts commit 5e9e06bd8360724bf82f3ada2e53da76f921a009.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 582711 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtLzVlOWUwNmJkODM2MDcyNGJmODJmM2FkYTJlNTNkYTc2ZjkyMWEwMDkM

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.linux/Linux%20Tests%20%28dbg%29%281%29%2832%29/52049

Sample Failed Step: network_service_browser_tests

Original change's description:
> NQE servicification of data saver proxy
> 
> Use network quality tracker instead of network quality estimator (NQE)
> to obtain network quality in data reduction proxy component.
> 
> Network quality tracker can provide network service when network
> service is enabled as well as when network service is disabled.
> 
> data_reduction_proxy_service.h receives network quality
> estimates on UI thread from network quality tracker.
> On receiving estimates, it posts them to d_r_p_io_data
> which lives on IO thread, and consumes the estimates.
> 
> Bug: 819244
> Cq-Include-Trybots: luci.chromium.try:linux_mojo
> Change-Id: I8a89fae921c15d5e006c9d51cb19cb6116688fb1
> Reviewed-on: https://chromium-review.googlesource.com/1171592
> Reviewed-by: Helen Li <xunjieli@chromium.org>
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
> Commit-Queue: Tarun Bansal <tbansal@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#582711}

Change-Id: Ida144bf271de7c3cf7a9794679c71ffcd9a55d07
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 819244
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Reviewed-on: https://chromium-review.googlesource.com/1173573
Cr-Commit-Position: refs/heads/master@{#582757}
27 files changed