Chrome Version: Chrome Canary 64.0.3279.0
OS: macOS 10.12.6

What steps will reproduce the problem?
(1) Click&Hold on the Profile Button so that the Menu appears.
(2) Now during the Click&Hold process move the mouse cursor over an item (e.g. Guest) on the Profile Menu.
(3) Release the mouse button

What is the expected result?
The Menu item should be highlighted in Step 2 and the item should be selected in Step 3. This would speedup the workflow.

What happens instead?
Nothing. You have to release the mouse button first, highlight the item and then click again on it.

Please use labels and text to provide additional information.
This is how the most OSX Buttons work. You can take the Hamburger/Settings Button or Back/Forward Buttons as a reference how it works. 

This would be a nice feature, since the behavior was changed to a click@hold possibility on the Profile Button with https://chromium-review.googlesource.com/789111.

Thanks :-)