bug(cdk/menu): menu is closed on mousedown event

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

14

Description

When menu is opened, using standalone trigger, it is closed by clicking outside the menu on mousedown event.

Reproduction

1. Go to the CDK menu examples page: https://material.angular.io/cdk/menu/examples.
2. Open the menu using "Click me!" button under "Menu with Standalone Trigger".
3. Click outside the menu.

Expected Behavior

Menu should be closed using mouseup event to comply with WCAG Level A - 2.5.2 criterion (https://www.w3.org/TR/WCAG21/#pointer-cancellation)

Actual Behavior

Menu is closed with mousedown event.
The same bahavior appears in CDK v15 - https://v15.material.angular.io/cdk/menu/examples
But not in v14 - https://v14.material.angular.io/cdk/menu/examples

Also latest Material Menu component works as expected - https://material.angular.io/components/menu/examples

Environment

• Angular: 15, 16
• CDK/Material: 15, 16
• Browser(s): latest Chrome, Firefox, Safari
• Operating System (e.g. Windows, macOS, Ubuntu): macOS (14.0 and 13.6)

L’issue pointe vers la page d’exemples de menus de CDK et son exemple standalone-trigger. Reproduisez d’abord le comportement outside-click, puis suivez la gestion des événements du menu CDK ; le travail est terminé lorsque le menu se ferme sur mouseup plutôt que sur mousedown, conformément au comportement WCAG attendu de Pointer-Cancellation et aux exemples de menus v14 et Material fonctionnels.