App Version: 61.0.3163.0 Canary
iOS Version: 10.3.2, 11.0 
Device: iPhone 
URL:

Steps to reproduce:
  1. Launch app
  2. Tap on omnibox
  3. Tap on qr scanner
  4. Tap Go
  5. Tap the omnibox again
  6. Tap qr scanner
  
Observed results: 
“Go” in Soft keyboard is disabled when using Qr scanner the second time.
Note: Using the same tab.

Expected results: 
“Go” in Soft keyboard should be enabled when using Qr scanner the second time.

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: NA, Safari: NA
Bug reproducible on current stable build (App Version, iOS Version):  No -M59 (new implementation)
Bug reproducible on the current beta channel build (App Version, iOS Version):No -M60 (new implementation)

Video:
https://drive.google.com/a/google.com/file/d/0B3EcbqLuR5TLeVJ6RkpFVU9BNXc/view