The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f4614212b9e9dff3a86a300f86487147a576075c

commit f4614212b9e9dff3a86a300f86487147a576075c
Author: Cooper Knaak <cooperknaak@google.com>
Date: Fri Jun 30 01:10:06 2017

[iOS] Add FeatureEngagementTracker factory.

Added FeatureEngagementTrackerFactory interface and implementation.

R=edchin@chromium.org, gchatz@chromium.org, sdefresne@chromium.org

Bug:  737818 
Change-Id: I32cff6432e90a1d781fbe4c0b1b6efa1496ddc67
Reviewed-on: https://chromium-review.googlesource.com/548200
Commit-Queue: Cooper Knaak <cooperknaak@google.com>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Ed Chin <edchin@chromium.org>
Reviewed-by: Gregory Chatzinoff <gchatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#483571}
[modify] https://crrev.com/f4614212b9e9dff3a86a300f86487147a576075c/ios/chrome/browser/DEPS
[modify] https://crrev.com/f4614212b9e9dff3a86a300f86487147a576075c/ios/chrome/browser/browser_state/BUILD.gn
[modify] https://crrev.com/f4614212b9e9dff3a86a300f86487147a576075c/ios/chrome/browser/browser_state/browser_state_keyed_service_factories.mm
[add] https://crrev.com/f4614212b9e9dff3a86a300f86487147a576075c/ios/chrome/browser/feature_engagement_tracker/BUILD.gn
[add] https://crrev.com/f4614212b9e9dff3a86a300f86487147a576075c/ios/chrome/browser/feature_engagement_tracker/OWNERS
[add] https://crrev.com/f4614212b9e9dff3a86a300f86487147a576075c/ios/chrome/browser/feature_engagement_tracker/feature_engagement_tracker_factory.h
[add] https://crrev.com/f4614212b9e9dff3a86a300f86487147a576075c/ios/chrome/browser/feature_engagement_tracker/feature_engagement_tracker_factory.mm