The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c72f3c4c940c6ada4e0447bfd2dd5dfdf532fdf1

commit c72f3c4c940c6ada4e0447bfd2dd5dfdf532fdf1
Author: jialiul <jialiul@chromium.org>
Date: Thu May 18 17:05:30 2017

Lose the user gesture expiration check on IdentifyReferrerChainByWebContents

This change will help better attribute HTML5 File API downloads and crx
extension download case.

BUG= 723089 

Review-Url: https://codereview.chromium.org/2892483002
Cr-Commit-Position: refs/heads/master@{#472849}

[modify] https://crrev.com/c72f3c4c940c6ada4e0447bfd2dd5dfdf532fdf1/chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.cc
[modify] https://crrev.com/c72f3c4c940c6ada4e0447bfd2dd5dfdf532fdf1/chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.h
[modify] https://crrev.com/c72f3c4c940c6ada4e0447bfd2dd5dfdf532fdf1/chrome/browser/safe_browsing/safe_browsing_navigation_observer_unittest.cc