App Version: 71.0.3578.13 Beta
iOS Version: 12.0, 11.4.1, 10.3.3
Device: iPhone only

Steps to reproduce:
1. Launch chrome app 
2. Load any webpage 
3. Go to full screen 
4. Change the device orientation

Observed results:
Notice that a Full screen exit

Expected results:
Shouldn’t exit full screen.

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: Not tested
Bug reproducible on Safari/Firefox: Firefox: No, Safari: No
Bug reproducible on current stable build (App Version, iOS Version): No on M69, Yes on M70 
Bug reproducible on the current beta channel build (App Version, iOS Version): Yes on M71 Beta 

Link to video:
https://drive.google.com/file/d/1_tQLkQSSzm6I4EDdFHsLU1zqMJT5MEro/view?usp=sharing