happened again, here's the crash id

Crash ID Chrome (Server ID: a3f72d6820000000)

Crash report uploaded on Tuesday, March 14, 2017 at 11:12:54 AM

Provide additional details

I found the root cause. will send a fix soon.

It looks already fixed in Issue 687232?

Per chat with yhanada@ offline, Issue 687232? is a different issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9f177cc7d313503e07a143337105868ef182022b

commit 9f177cc7d313503e07a143337105868ef182022b
Author: yhanada <yhanada@chromium.org>
Date: Wed Mar 15 06:03:11 2017

Fix crash when removing all notifications by "Clear all" button.

BUG= 701348 

Review-Url: https://codereview.chromium.org/2750853005
Cr-Commit-Position: refs/heads/master@{#457005}

[modify] https://crrev.com/9f177cc7d313503e07a143337105868ef182022b/ui/arc/notification/arc_custom_notification_view.cc
[modify] https://crrev.com/9f177cc7d313503e07a143337105868ef182022b/ui/message_center/message_center_impl.cc

Your change meets the bar and is auto-approved for M58. Please go ahead and merge the CL to branch 3029 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), bhthompson@(ChromeOS), govind@(Desktop)

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This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

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Clearing added cc list by sheriffbot. sorry for the spam. thanks.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ca74b3b18d45dbc81f3869d04ec51bdd95f51d57

commit ca74b3b18d45dbc81f3869d04ec51bdd95f51d57
Author: yhanada <yhanada@chromium.org>
Date: Tue Mar 21 05:33:44 2017

Fix crash when removing all notifications by "Clear all" button.

BUG= 701348 

Review-Url: https://codereview.chromium.org/2750853005
Cr-Commit-Position: refs/heads/master@{#457005}
(cherry picked from commit 9f177cc7d313503e07a143337105868ef182022b)

Review-Url: https://codereview.chromium.org/2762933002 .
Cr-Commit-Position: refs/branch-heads/3029@{#318}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}

[modify] https://crrev.com/ca74b3b18d45dbc81f3869d04ec51bdd95f51d57/ui/arc/notification/arc_custom_notification_view.cc
[modify] https://crrev.com/ca74b3b18d45dbc81f3869d04ec51bdd95f51d57/ui/message_center/message_center_impl.cc