UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.75 Safari/537.36

Steps to reproduce the problem:
1. Install KDE 5. Use the default Breeze theme. 
2. Install Chrome 50
3. Upgrade to Chrome 51
4. http://imgur.com/a/fbxut

What is the expected behavior?
My browser doesn't look like Opera from 1999.

What went wrong?
I have no idea. Is this redesign (for the worse as always) or is some new integration library missing?

Did this work before? Yes Chrome 50

Chrome version: 52.0.2743.82-1  Channel: stable
OS Version: 4.6.4-1-ARCH
Flash Version: Shockwave Flash 22.0 r0