App Version: 69.0.3497.43 beta
iOS Version: iOS 11.4,iOS 12
Device: iPhones only 

Steps to reproduce:
1. Launch Chrome 
2. Scroll down the pull to refresh.
3. Release reload from pull to refresh and tap on search button simultaneously.

Observed results:
Omnibox disappears

Expected results:
Omnibox should not disappear.

Number of times you were able to reproduce: 3/5
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 Dolphin/Safari/Firefox: NA
Bug reproducible on the current beta channel build : NA New UI on M68
Bug reproducible on the current beta channel build : Yes in M69

Link to video/image:
Video :
https://drive.google.com/file/d/1Tnqa3QDKtUpjB1yETVuOFPznvCJdOkHv/view?usp=sharing

https://drive.google.com/file/d/1ZgUcEa7oaij-trgp_gRazaxwsJE48MSh/view?usp=sharing