App Version:72.0.3626.64
iOS Version: 12.1.2, 12.1.1 only (issue not repro on iOS 11 devices)
Device: iPhone Xr, iPhone 5s, iPad 6th gen

Steps to reproduce:
1.Launch Chrome
2.Navigate to any article --> Add it to read later
3.Navigate to the reading list --> Long tap on the article --> tap on View offline version in New Tab
4.Enter tab switcher mode → Exit tab switcher mode → Observe
 
Observed results: White patch is seen for a moment on offline version of Reading list article on exiting tab switcher mode
Expected results: White patch should not be seen on offline version of Reading list article on exiting tab switcher mode

Number of times you were able to reproduce: 5/5
Bug reproducible after clean install:Yes
Bug reproducible after clearing cache and cookies:Yes
Observed behavior in Chrome Mobile on Android:No 
Check for similar behavior on Firefox/Safari:NA
Bug reproducible on current stable build (App Version, iOS Version): No on 71.0.3578.89, iOS Version- 12.1.2,12.1.1
Bug reproducible on the current beta channel build (App Version, iOS Version):Yes on 72.0.3626.64, , iOS Version- 12.1.2, 12.1.1