Confirmed. Looks like a regression to me.

Able to reproduce the issue on the latest canary(55.0.2846.0) on Window=10, Mac OS 10.11.6 and Linux Ubuntu 14.04.

This is a regression issue broken in M-54.

Last good build: 54.0.2817.0
First bad build: 54.0.2819.0

Changelog from Bisect tool: 

https://chromium.googlesource.com/chromium/src/+log/6526c5b4ac92c26c3903146941ceb267422ebf8c..8dfa12f1b8845bc912728471d19d9915119456d7

aberent@: Could you please take a look at this and confirm if the above suspect from the bisect tool is related.

Thank you!

Please have the fix baked in canary and merged to 2840 branch before 09/05 Monday for Dev Release Scheduled on Tuesday 09/06.The same will be promoted to Beta on 09/08.

I have been on vacation. I will take a look, but that CL seems unlikely, since it was supposed to only change anything on Android.

I can't reproduce this (with 25 bookmarks) with a local Linux build from master. Any other clues on how to reproduce?

I can now reproduce this on 55.0.2845.0; but not on a local Linux build from master. I have tried both debug and release official builds. I still think this is very unlikely to be my CL; how exactly was this tested with the bisect tool?

ajha@: Can you please recheck the regression range? Thanks in advance. 

Stranger and stranger! I have just realised that the behaviour I am seeing in the build I downloaded is the opposite of that reported in the original bug. Namely when the bookmark bar is hidden I only see a few bookmarks in the bookmark manager, but when it is visible I see them all.

See the attached images.

Note that, when I remove the bookmark bar, the list of bookmarks in the bookmark manager only changes when I refresh the page.

Deleted: Screenshot from 2016-09-05 19:50:45.png 147 KB

	Screenshot from 2016-09-05 19:50:45.png 147 KB View Download

Deleted: Screenshot from 2016-09-05 19:51:28.png 271 KB

	Screenshot from 2016-09-05 19:51:28.png 271 KB View Download

Hmm, I've tested the situation, so let's make it clear. 

-chrome://bookmarks shows *incomplete* list of bookmarks whether you use attached/detached BMB
-chrome://bookmarks shows *complete* list of bookmarks when you change the BMB behaviour (make detached BMB attached or vice versa) while you are on the page chrome://bookmarks:
   +If you use detached BMB,go to chrome://bookmarks you will see *incomplete* list. Make BMB attached, the page will show *complete* list (No need to refresh).
   +If you use attached BMB,go to chrome://bookmarks you will see *incomplete* list. Make BMB detached, the page will show *complete* list (No need to refresh).

Okay, I did a deeper bisect and the regression range is this: https://chromium.googlesource.com/chromium/src/+log/67b240c6628573aa3437e14fc82edcb7de78e944..8dfa12f1b8845bc912728471d19d9915119456d7

Probably this is the culprit: https://codereview.chromium.org/2205843003

rune@opera.com: Can you please check, if your change is breaking the Bookmarks Manager?

Thanks in advance!

Not verified, but since this is in the same regression range and also for chrome://bookmarks I suspect it's the same as  issue 634704 .

CR 634704 fixed.  Merged to m54 beta today, will appear with next beta update (~10/5?)