I'm going to mark this Pri-3.

Since we're using NSMenuItem for these menus, there's no good way for us to tell whether the item is getting elided or not, which makes it complex to tell whether there "should be" a tooltip or not. The unnecessary tooltips shouldn't be there, but I don't think this has a good importance-to-effort ratio.

This bug is tagged as regression.Which means that the bisects are incorrect or do not have an owner who is actively investigating.
Requesting the reporter to triage and update the behavior in all the latest chrome channels and bisect if needed.Close as WontFix if not reproducible.

I will handle this issue.

I upload CL for this issue. (https://codereview.chromium.org/2504753003/)
I also upload screen shot to show how it works.

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	short_name.png 146 KB View Download

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	long_name.png 137 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/efa1d76a70dfec345ff89d2ca978a46029c51e7e

commit efa1d76a70dfec345ff89d2ca978a46029c51e7e
Author: corona10 <corona10@gmail.com>
Date: Mon Nov 21 16:38:55 2016

Bookmarks bar, unnecessary tooltip is seen for folders with small name.

BUG= 635836 

Review-Url: https://codereview.chromium.org/2504753003
Cr-Commit-Position: refs/heads/master@{#433563}

[modify] https://crrev.com/efa1d76a70dfec345ff89d2ca978a46029c51e7e/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.mm
[modify] https://crrev.com/efa1d76a70dfec345ff89d2ca978a46029c51e7e/chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller_unittest.mm

Thanks for the patch!