Chrome Version       : 63.0.3239.116
OS Version: 10032.75.0
URLs (if applicable) :
Other browsers tested:
  Add OK or FAIL after other browsers where you have tested this issue:
     Safari:
    Firefox:
    IE/Edge:

What steps will reproduce the problem?
1.Enable strict site isolation flag
2.Start Gmail in standard mode
3.Gmail doesn't load
4. Disable strict site isolation flag
5. Start Gmail in standard mode
6. Gmail loads as expected

What is the expected result?


What happens instead of that?


Please provide any additional information below. Attach a screenshot if
possible.

UserAgentString: Mozilla/5.0 (X11; CrOS x86_64 10032.75.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.116 Safari/537.36