App Version: 64.0.3282.7 beta
iOS Version: 11.2
Device: iPhoneX only
URL: http://browsingtest.appspot.com/external_url.html

Steps to reproduce:
  1. Launch Google Chrome
  2. Navigate to the above URL (http://browsingtest.appspot.com/external_url.html)
  3. Pich zoom a little bit so that its possible to enter fullscreen mode
  4. Enter fullscreen mode
  5. Tap on the second link in the page "App Store URL (itms scheme)"
  6. Cancel the alert when present

Observed results: Observe that toolbar disappeared. 

Expected results: Toolbar should be displayed.

Note: Scrolling up and down fixes the issue.

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): M62 NO
Bug reproducible on the current beta channel build (App Version, iOS Version): M63 NO

Link to video/image: https://drive.google.com/file/d/1eoaJhzMLB0qwyAwxVQwg2tERV5LpyRIS/view