UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3068.1 Safari/537.36

Steps to reproduce the problem:
1. Visit https://editor.construct.net/
2. Open dev tools and start recording in the Performance tab
3. Hover the mouse cursor back and forth over the border shown with a red circle here: https://dl.dropboxusercontent.com/u/15217362/chrome-mousehover-area.png
You should see the cursor changing rapidly between a normal cursor and a horizontal resize cursor.
4. Stop recording and inspect timeline results

What is the expected behavior?
Changing the mouse cursor should not have any significant performance impact.

What went wrong?
On a high-end desktop machine, changing the mouse cursor causes a ~20ms "Recalculate Style" as shown here: https://dl.dropboxusercontent.com/u/15217362/chrome-mousehover-timing.png

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 59.0.3068.1  Channel: canary
OS Version: 10.0
Flash Version: