UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.106 Safari/537.36

Steps to reproduce the problem:
1. visit http://www.elperiodico.com/es/noticias/ocio-y-cultura/bienal-venecia-2017-catalunya-antoni-abad-ciegos-blindwiki-5281734
2. Right click and choose "translate to English" (or whatever your locale language is)
3. hover with the cursor over some paragraph or text

What is the expected behavior?
The original text is displayed in a sort of popup near to the cursor.
This popup should be opaque or semitransparent with enough alpha to make sure that the text is readable

What went wrong?
The layout of the popup with the original text is completely broken. There's a useless grey rectangle on the top, and below it the text is black on a completely transparent background, hence completely unreadable.

Did this work before? N/A 

Chrome version: 51.0.2704.106  Channel: n/a
OS Version: 
Flash Version: Shockwave Flash 22.0 r0