The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c25e5659d04787c589653e3755842ad8c56a19fb

commit c25e5659d04787c589653e3755842ad8c56a19fb
Author: Tarun Bansal <tbansal@chromium.org>
Date: Fri Nov 16 21:06:49 2018

Enable DataReductionProxyMainMenu by default

Enable DataReductionProxyMainMenu by default. This has been
enabled for 99% of population for over a year.

Also, remove the variation param
"persistent_menu_item_enabled"
since we decided not to launch with that setting.
See the bug for more details.

Change-Id: I551f90132e3a5daaedd544cd7847c0949400f09f
Bug:  905911 
Reviewed-on: https://chromium-review.googlesource.com/c/1338883
Reviewed-by: Megan Jablonski <megjablon@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608939}
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/chrome/android/java/src/org/chromium/chrome/browser/net/spdyproxy/DataReductionProxySettings.java
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/chrome/android/javatests/src/org/chromium/chrome/browser/appmenu/DataSaverAppMenuTest.java
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/chrome/browser/about_flags.cc
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/chrome/browser/android/chrome_feature_list.cc
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/components/data_reduction_proxy/core/common/data_reduction_proxy_features.cc
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/components/data_reduction_proxy/core/common/data_reduction_proxy_features.h
[modify] https://crrev.com/c25e5659d04787c589653e3755842ad8c56a19fb/testing/variations/fieldtrial_testing_config.json