Able to reproduce the issue on mac 10.12.6 non retina using chrome reported version #64.0.3275.0. Issue is specific to mac non retina.

Bisect Information:
=====================
Good build: 64.0.3274.0    Revision(518061)
Bad Build : 64.0.3275.0    Revision(518486)

Change Log URL: 
https://chromium.googlesource.com/chromium/src/+log/a65bd9a1eb35ad0259c271702dcb27b0e845fe08..f168a3d0f47f69345d88b462b1b73e429ee7dd6e

From the above change log suspecting below change
Change-Id: I7692b052886974389d45bb176c71f34d94eb269c
Reviewed-on: https://chromium-review.googlesource.com/781301

patricialor@ - Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.
Note: Adding label ReleaseBlock-Stable as it seems to be a recent regression.

Thanks...!!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e717e13a06e58a5a04dea5731fa828e310ff38fc

commit e717e13a06e58a5a04dea5731fa828e310ff38fc
Author: Patti <patricialor@chromium.org>
Date: Thu Nov 23 10:58:55 2017

MacViews/Profile Chooser: No initial focused View when full keyboard access off.

Buttons are not focusable on Mac when full keyboard access is turned off. In the
|ProfileChooserView|, a button is returned in
WidgetDelegate::GetInitiallyFocusedView(), causing Widget::SetInitialFocus() to
fail and fall back to focusing the first focusable View instead. This focuses
one of the |HoverButtons| in |ProfileChooserView|, which are always focusable
despite full keyboard access (see r518213) because they are designed to be used
as a menu. However, opening a menu does not typically focus the first menu item
on behalf of the user, so avoid this behavior by checking whether full keyboard
access is off first.

Bug:  787885 
Change-Id: Ie1a92879b31720be4921450677bb3cbdf5b77ec5
Reviewed-on: https://chromium-review.googlesource.com/786830
Reviewed-by: Trent Apted <tapted@chromium.org>
Commit-Queue: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518885}
[modify] https://crrev.com/e717e13a06e58a5a04dea5731fa828e310ff38fc/chrome/browser/ui/views/profiles/profile_chooser_view.cc

Thanks for fixing that bug.

Thanks mehmet@ for always filing them! It is much appreciated :)

Verified this issue on MacBook Air 10.12.6 using chrome latest canary #64.0.3277.0 following steps mentioned in the original comment. Observed no default focus in the first row after clicking profile button as expected, hence adding TE-Verified label for M64.

Thanks!

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