Version : Chrome Canary 68.0.3431.0
Device  : iPad
iOS     : 11.3.1, 10.3.3

Preconditions
#ui-refresh-phase-1 enabled

Steps to reproduce:
1. Launch Chrome
2. Open number of tabs.(Ex- I had about 60+ tabs open)

Observed Results:
Black shade seen when numerous tabs are opened in iPad.


Expected results: 
Black shade should not be seen when numerous tabs are opened in iPad.


Number of times you were able to reproduce: 5/5
Bug reproducible after clean install: Yes
Bug reproducible after clearing cache and cookies: Yes
Bug reproducible on Chrome Mobile on Android: NA
Bug reproducible on Safari/Firefox: Firefox: NA, Safari: NA
Bug reproducible on current stable build (App Version, iOS Version): NA on M66
Bug reproducible on the current beta channel build (App Version, iOS Version): NA on M67
Link to video/image: 
https://drive.google.com/file/d/0B6GVWQnhaMClNkNQcm1DVi04c0E/view?usp=sharing