GitLab

This CL addresses crbug.com/1072350 by adding two UseCounters:

 - One to count requests whose
    - method != ("GET" || "HEAD")
    - mode == kNoCors
    - response is opaque
 - Another to count requests that meet the same criteria as above, but
   have experienced at least one redirect.

This CL also adds tests to ensure that the UseCounter is counted
properly:

  Tests:
    - Not enough conditions are met for the UseCounter:
       - No conditions met: (GET, "cors", basic)
       - One condition met: (POST, "cors" basic)
       - One condition met: (GET, "no-cors" basic)
       - One condition met: (GET, "no-cors", opaqueredirect)
       - Two condition met: (POST, "no-cors", basic)
       - Two condition met: (GET, "no-cors", opaque)
    - All conditions are met:
       - (POST, "no-cors", opaque): Cross-origin, no redirect
         - Should count first counter, but not second
       - (POST, "no-cors", opaque): Cross-origin Redirect involved
         - Should count both UseCounters

R=kinuko@chromium.org, ricea@chromium.org, yhirano@chromium.org

Bug: 1072350
Change-Id: I13331a8ca51a9cdd684ddb8b88f3232117426320
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2242205
Commit-Queue: Dominic Farolino <dom@chromium.org>
Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#778021}