Linux scrollbar continues scrolling on hover after context menu.

On Gubuntu 14.04 + Chrome 61.0.3163.100 (Official Build) (64-bit)
(1) Open a webpage that has enough content to scroll
(2) Left-click and drag on the scrollbar slider
(3) While dragging, right-click to open a web content context menu
(4) Let go of the left mouse button (realizing the mistaken menu)
(5) Left-click outside the menu to dismiss it
(6) Hover in the page and in the scrollbar area
Expected: The scrollbar has lost tracking of the mouse.
Actual: The scrollbar is still tracking hover over its visible bounds.

This is odd, but not awful, you can escape with a scrollbar left-click.