UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.89 Safari/537.36

Steps to reproduce the problem:
1. run debian x64 (8 or higher), or ubuntu x64 15.10
2. upgrade chrome/chromium to 45 or higher
3. show bookmar bar, click a bookmark folder, move mouse hovering a google's item(eg. scholar, gmail)

What is the expected behavior?
no delay on the hovering, 
should act as chrome 44 and before

What went wrong?
higher CPU usage

Did this work before? N/A 

Chrome version: 45 - 49  Channel: stable
OS Version: debian & ubuntu
Flash Version: non

chrome version 44 and before don't have this bug