App Version: 70.0.3538.6 beta
iOS Version: 10.3.3, 11.4.1
Device: iPhone,iPad

Steps to reproduce:
1. Launch chrome.
2. Perform a search (say : test pdf)
3. Tap on any test pdf link wait for the page to load.
4. Tab on tab switcher button

Observed results:
Google SRP result are shown in tabgrid view.

Expected results:
PDF page should be seen in tabgrid view.

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 Dolphin/Safari/Firefox: NA
Bug reproducible on the current beta channel build : No in M69
Bug reproducible on the current beta channel build : Yes in M70

Link to Video :
M70 :
https://drive.google.com/file/d/1nvHDJxRXkOhI2pmu7x7mMYJ009T-ihkQ/view?usp=sharing

M69 :
https://drive.google.com/file/d/1CivU9BOzt_FzIyKip9dVGfIzN-FZrAsz/view?usp=sharing