In addition, there should be only two mechanisms to enable experiments, the variations framework and the command line and the latter should override the former. Moreover, DataReductionProxyServerExperiments should be the only experiment to set a data reduction proxy experiment.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7e309dd054ce82c89ff193ca57f559d025ccbe4d

commit 7e309dd054ce82c89ff193ca57f559d025ccbe4d
Author: ryansturm <ryansturm@chromium.org>
Date: Wed May 24 16:29:53 2017

Add an about:flag to support alternative data saver features

This flag allows an alternative back end Data Saver implementation to be
used by chrome. This may result in different types of previews served,
different triggering mechanisms, or other back end changes that are not
used by default.

This also fixes the CP header having multiple "exp" directives.

BUG=721113, 656195 

Review-Url: https://codereview.chromium.org/2887423002
Cr-Commit-Position: refs/heads/master@{#474320}

[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/chrome/browser/about_flags.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/content/browser/content_lofi_decider.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/content/browser/content_lofi_decider.h
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/content/browser/content_lofi_decider_unittest.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate_unittest.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options_unittest.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/common/data_reduction_proxy_headers.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.cc
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/components/data_reduction_proxy/core/common/lofi_decider.h
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/tools/chrome_proxy/webdriver/lite_page.py
[modify] https://crrev.com/7e309dd054ce82c89ff193ca57f559d025ccbe4d/tools/metrics/histograms/enums.xml

Making available for reassignment 

ryansturm@, please update or close this bug (as obsolete) depending on your plans for a flag refactor.