The related code is at https://cs.chromium.org/chromium/src/ui/webui/resources/cr_elements/cr_profile_avatar_selector/. I am able to reproduce this on Linux too, not just Mac.

+dbeam, just FYI.

So it seems that something is wrong within the involved Polymer "select-y" behaviors [1]. Specifically see screencast where the avatar being selected is immediately de-selected. I am not aware yet of what triggers the 2nd call. Perhaps the problem can be sidestepped by making cr-profile-avatar-selector-grid to not use the IronMenuBehavior [2].


[1] https://cs.chromium.org/chromium/src/third_party/polymer/v1_0/components-chromium/iron-selector/iron-selectable-extracted.js?l=319
[2] https://cs.chromium.org/chromium/src/ui/webui/resources/cr_elements/cr_profile_avatar_selector/cr_profile_avatar_selector_grid.js?l=14

Deleted: selection_changes_too_often.mp4 470 KB

	selection_changes_too_often.mp4 470 KB View Download

FYI, I am attempting to re-implement the grid's functionality without IronMenuBehavior (and fixing the bug at the same time, [1]). I initially spent some time digging into all the involved behaviors, until I stopped because it seemed overly complicated for the task at hand.

I don't know if my attempt will succeed, but looks promising so far. Will report back in this thread.

[1] https://codereview.chromium.org/2950943002 still WIP

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e67dbad97952415cabff9444ed85f543579240e6

commit e67dbad97952415cabff9444ed85f543579240e6
Author: dpapad <dpapad@chromium.org>
Date: Fri Jun 23 01:54:31 2017

MD Settings: Stop using IronMenuBehavior from cr-profile-avatar-selector-grid.

This both simplifies the code and fixes the selection bug. The original
code relied on multiple inherited Polymer behaviors which stomped on each other
causing what seems like a race condition per findings at
https://bugs.chromium.org/p/chromium/issues/detail?id=734789#c2.

Specifically:
 - Simplify logic within cr-profile-avatar-selector-grid, no more inherited
   behaviors.
 - Update both settings/ and md_user_manager/ client code.
 - Stop relying on bubbling 'iron-activate' event in manage_profile.html.
   Instead use a Polymer binding + observer.

Regarding the race condition: The previous code, was seemingly attempting to
highlight the grid with the currently selected avatar icon on creation, but
unsuccessfully because this was intentionally broken within the C++ side at
 crbug.com/710660 . As a side-effect, the 'profile-info-changed' event
propagating back from C++ after every user-initiated change, was causing the
selection of the user to be immediately discarded.

It would make little sense to re-implement JS functionality that is already not
working. Instead I am removing such tests, since they are meaningless until/if
the C++ side is fixed.

BUG= 734789 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2950943002
Cr-Commit-Position: refs/heads/master@{#481776}

[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/chrome/browser/resources/md_user_manager/create_profile.html
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/chrome/browser/resources/md_user_manager/create_profile.js
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/chrome/browser/resources/settings/people_page/manage_profile.html
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/chrome/browser/resources/settings/people_page/manage_profile.js
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/chrome/browser/resources/settings/people_page/people_page.html
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/chrome/test/data/webui/cr_elements/cr_profile_avatar_selector_tests.js
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/chrome/test/data/webui/md_user_manager/create_profile_tests.js
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/chrome/test/data/webui/settings/people_page_manage_profile_test.js
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/ui/webui/resources/cr_elements/cr_profile_avatar_selector/compiled_resources2.gyp
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/ui/webui/resources/cr_elements/cr_profile_avatar_selector/cr_profile_avatar_selector.html
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/ui/webui/resources/cr_elements/cr_profile_avatar_selector/cr_profile_avatar_selector.js
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/ui/webui/resources/cr_elements/cr_profile_avatar_selector/cr_profile_avatar_selector_grid.html
[modify] https://crrev.com/e67dbad97952415cabff9444ed85f543579240e6/ui/webui/resources/cr_elements/cr_profile_avatar_selector/cr_profile_avatar_selector_grid.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/16d4bfed7e1a4f29cdc9e471dbaaddfd12419e50

commit 16d4bfed7e1a4f29cdc9e471dbaaddfd12419e50
Author: dpapad <dpapad@chromium.org>
Date: Mon Jun 26 22:59:07 2017

MD Settings: Tweak selected avatar border in selection grid.

Per UX request, it should be 2px instead of 1px. Also removing unused
--avatar-selector-avatar-selected CSS mixin.

BUG= 734789 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2956953002
Cr-Commit-Position: refs/heads/master@{#482450}

[modify] https://crrev.com/16d4bfed7e1a4f29cdc9e471dbaaddfd12419e50/ui/webui/resources/cr_elements/cr_profile_avatar_selector/cr_profile_avatar_selector.html

> the selected state should be 2px GoogleBlue500 <-- This is new and true for all platforms

Fixed.

> the selected state should be present upon opening chrome://settings/manageProfile

Tracked by  issue 710660 , and it was a tradeoff we made to have high DPI icons (see details in that bug). Fixing this seems more involved.

> 1 click is required to toggle between avatars. It should take 1 click to toggle the selected state

Fixed.