The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/05a91e2d034b4495852b5ed6be69ab933a921079

commit 05a91e2d034b4495852b5ed6be69ab933a921079
Author: Joy Ming <jming@chromium.org>
Date: Tue Jul 25 16:02:57 2017

Move the logic for notification creation to DownloadNotificationFactory.

This is the first step in a refactor to make downloads a foreground
service. This step moves the logic of notification creation from
DownloadNotificationService into the newly constructed
DownloadNotificationFactory through the passing of a DownloadUpdate
object. This intermediate step ensures that the notifications are still
being rendered correctly. Eventually, all of the notification logic
(creation, updating, and removal) will be managed by this new class.

Bug:  747564 , 747563 
Change-Id: Ie44a76de4d61f2a6ad1bac0e0fd05ce9d63c1816
Reviewed-on: https://chromium-review.googlesource.com/572038
Commit-Queue: Joy Ming <jming@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Min Qin <qinmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#489321}
[modify] https://crrev.com/05a91e2d034b4495852b5ed6be69ab933a921079/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
[add] https://crrev.com/05a91e2d034b4495852b5ed6be69ab933a921079/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationFactory.java
[modify] https://crrev.com/05a91e2d034b4495852b5ed6be69ab933a921079/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationService.java
[add] https://crrev.com/05a91e2d034b4495852b5ed6be69ab933a921079/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUpdate.java
[modify] https://crrev.com/05a91e2d034b4495852b5ed6be69ab933a921079/chrome/android/java_sources.gni