Chrome Version       : 50.0.2661.94 (Official Build) (64-bit)
URLs (if applicable) : N/A
Other browsers tested: N/A

What steps will reproduce the problem?
(1) Download and install attached test extension.
(2) Open the Options page for the Cursor Update Testing extension.
(3) Move cursor over the gray "Move Cursor Here, Click, and Hold" text, click the left mouse button, and hold.

What is the expected result?
When holding the mouse button down over the gray text the cursor should change to the -webkit-grabbing cursor (closed hand) and after releasing the mouse button it should be changed back to the -webkit-grab cursor (open hand).

What happens instead?
When holding the mouse button over the gray text the cursor remains as the -webkit-grab cursor (open hand) until the mouse button is released or the mouse is moved. After releasing the mouse button it then remains as the -webkit-grabbing cursor (closed hand) until the mouse button is again clicked or the mouse moved.

Please provide any additional information below. Attach a screenshot if
possible.
I'm working on implementing dragging for some settings in my extension and noticed that when the cursor is changed in mousedown/mouseup event listeners on an extension's options page (to indicate a drag in progress for instance), the cursor doesn't actually change until the mouse button is later released/clicked or the mouse is moved. The attached video illustrates the problem which occurs on both Mac OS X 10.9 and Windows 10. Note that I added a status display to the page which will show the status of the mouse button and what cursor should be displayed.

Finally, this problem does NOT occur if you change the options page to open in a tab (change open_in_tab in the manifest.json file to true) or if you just open the extension's Options_UI.html file directly.
 

Deleted: Cursor Update Testing.zip 3.1 KB

Cursor Update Testing.zip 3.1 KB Download

Deleted: Cursor Update Testing Demonstration Video.mp4 366 KB

Cursor Update Testing Demonstration Video.mp4 366 KB Download