[ios] Add more tests to url loading service

Put a better fix for cross service request (incognito / normal).
Test open in current or new tab.
Test cross requests.

Bug: 907527
Change-Id: I9e3032e1510ffeaf691506383b3baf14d956eab5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1625995
Commit-Queue: David Jean <djean@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663045}
6 files changed