Correction:
Android Build Number: 7.0/NRD91N

Additional comments:
This issue is present on all the builds of M55, M56 and M57 milestones
This issue is present on Android N devies ex. Nexus 9 (7.0/NRD91N), Google Pixel (7.1/NDE63V), Google Pixel XL (7.1/NDE63V) and LG Nexus 5X (7.0/NRD90R)

Please find logs and Video @ http://go/chrome-androidlogs1/6/674015

Looks like what N's automatically grouping notifications.  Guessing that's a feature.

Actually, going to reopen this but make it more general.

https://android-developers.googleblog.com/2016/06/notifications-in-android-n.html

Unless you manually bundle your notifications, Android N will collapse them all together and pick a random icon for it.  This is suboptimal because a bunch of icons will end up behind an Incognito icon (e.g. in the video for comment #2).  There's probably a better way to handle this than letting Android do what it wants.

+ CC'ing folks who have dealt with notifications or might have to deal with notifications in the future

+ Adding Media notifications and Physical Web to the notification party

+ Adding sync peeps.
( //chrome/android/java/src/org/chromium/chrome/browser/sync/SyncNotificationController.java )

A quick update, if we perform the same set of steps in non-incognito mode, the download notification icon stays and works as the aforementioned expected result

Let's make this public.

The issue is targeted for M-56 — while the fixes will be small, non-controversial and safe, Beta's already released so we should consider punting given that the population on N is still rather small.

Re #9:
They start bundling at 4, so if you're still at 3 (without the incognito icon) you're good.

+shaktisahu@

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/318c5ae5cb37a664c2f068fa2095d293bfc50bcd

commit 318c5ae5cb37a664c2f068fa2095d293bfc50bcd
Author: dfalcantara <dfalcantara@chromium.org>
Date: Fri Jan 06 20:03:57 2017

Group Downloads notifications, and separate Incognito

* Download notifications are grouped together, and Incognito
  is put into its own group.  Summary notifications will come
  in a later patch; Android N doesn't seem to bundle these
  together once they're in their own group, making it hard
  to debug without Android Wear.

* New and existing group name constants are moved into
  NotificationConstants.java.

* Cleans up DownloadNotificationService's constant naming
  schemes to make it clearer what each field does.

BUG=678694, 674015 

Review-Url: https://codereview.chromium.org/2619433003
Cr-Commit-Position: refs/heads/master@{#442017}

[modify] https://crrev.com/318c5ae5cb37a664c2f068fa2095d293bfc50bcd/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadNotificationService.java
[modify] https://crrev.com/318c5ae5cb37a664c2f068fa2095d293bfc50bcd/chrome/android/java/src/org/chromium/chrome/browser/incognito/IncognitoNotificationManager.java
[modify] https://crrev.com/318c5ae5cb37a664c2f068fa2095d293bfc50bcd/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
[modify] https://crrev.com/318c5ae5cb37a664c2f068fa2095d293bfc50bcd/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationConstants.java
[modify] https://crrev.com/318c5ae5cb37a664c2f068fa2095d293bfc50bcd/chrome/android/javatests/src/org/chromium/chrome/browser/download/DownloadNotificationServiceTest.java

Removing downloads component because it was being tracked by 678694.

Incognito, downloads, and media notifications are all currently assigned a different group and don't get grouped together.  Haven't seen any CLs for the other kinds of notifications.

I just uploaded https://codereview.chromium.org/2628723003/ for push notifications - there's also one in progress for sync notifications by peter@

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e424e1f96c68e959d2980c2f50ac3cee6a50dde9

commit e424e1f96c68e959d2980c2f50ac3cee6a50dde9
Author: awdf <awdf@chromium.org>
Date: Thu Jan 12 17:55:27 2017

Android notifications: set group for push notifications

- Push notifications are no longer grouped with all other Chrome
  notifications

- However, this patch makes them standalone, rather than grouped by
  origin, as we aren't yet setting a summary notification.

BUG= 674015 ,674335

Review-Url: https://codereview.chromium.org/2628723003
Cr-Commit-Position: refs/heads/master@{#443285}

[modify] https://crrev.com/e424e1f96c68e959d2980c2f50ac3cee6a50dde9/chrome/android/java/src/org/chromium/chrome/browser/notifications/CustomNotificationBuilder.java
[modify] https://crrev.com/e424e1f96c68e959d2980c2f50ac3cee6a50dde9/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationBuilderBase.java
[modify] https://crrev.com/e424e1f96c68e959d2980c2f50ac3cee6a50dde9/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationConstants.java
[modify] https://crrev.com/e424e1f96c68e959d2980c2f50ac3cee6a50dde9/chrome/android/java/src/org/chromium/chrome/browser/notifications/StandardNotificationBuilder.java
[modify] https://crrev.com/e424e1f96c68e959d2980c2f50ac3cee6a50dde9/chrome/android/javatests/src/org/chromium/chrome/browser/notifications/CustomNotificationBuilderTest.java
[modify] https://crrev.com/e424e1f96c68e959d2980c2f50ac3cee6a50dde9/chrome/android/javatests/src/org/chromium/chrome/browser/notifications/StandardNotificationBuilderTest.java

This issue is fixed on latest M57 Thanks!