The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/90ff28572960783445f687e331b88fda89712b74

commit 90ff28572960783445f687e331b88fda89712b74
Author: Ryan Sturm <ryansturm@chromium.org>
Date: Thu Dec 14 21:51:50 2017

Adding per host data savings for offline previews

This tracks per host data savings for offline previews as well as
cleaning up the code somewhat.

Bug:  794642 
Change-Id: I2660beeee2c6ef8f7939eff4861b78203dab63d6
Reviewed-on: https://chromium-review.googlesource.com/825362
Commit-Queue: Ryan Sturm <ryansturm@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524194}
[modify] https://crrev.com/90ff28572960783445f687e331b88fda89712b74/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_io_data.cc
[modify] https://crrev.com/90ff28572960783445f687e331b88fda89712b74/chrome/browser/previews/previews_infobar_delegate.cc
[modify] https://crrev.com/90ff28572960783445f687e331b88fda89712b74/chrome/browser/previews/previews_infobar_delegate.h
[modify] https://crrev.com/90ff28572960783445f687e331b88fda89712b74/chrome/browser/previews/previews_infobar_tab_helper.cc
[modify] https://crrev.com/90ff28572960783445f687e331b88fda89712b74/chrome/browser/previews/previews_infobar_tab_helper_unittest.cc
[modify] https://crrev.com/90ff28572960783445f687e331b88fda89712b74/components/data_reduction_proxy/core/browser/data_reduction_proxy_compression_stats.h
[modify] https://crrev.com/90ff28572960783445f687e331b88fda89712b74/components/data_reduction_proxy/core/browser/data_reduction_proxy_compression_stats_unittest.cc