UserAgent: Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2824.0 Safari/537.36

Steps to reproduce the problem:
1. Open bookmark manager - takes >10 secs
2. Try and open a bookmark, takes >10 secs, also causes tab switching to take several seconds.
3. Opening bookmark fails as double clicks don't work - presumably due to the lag.

What is the expected behavior?

What went wrong?
Bookmark manager has become unusable. Takes ages to respond to any request -- ie load page takes ages, then scroll, click a folder.. wait ages... Double click a bookmark, page never opens. Can only open a bookmark by clicking the pull down arrow at right, then wait a while for menu to appear, then click open in new tab.

While bookmark tab is trying to work, clicking another tab takes several seconds to respond.

Chrome task manager shows nothing unusual!!

Once bookmark manager tab is closed, everything is fine.

Did this work before? Yes 

Chrome version: 54.0.2824.0  Channel: dev
OS Version: 6.2 (Windows 8)
Flash Version: Shockwave Flash 22.0 r0