GitLab

This CL isolates activation-gated APIs from the tests because those API
behavior may depend on other browser-defined things.

Four specific changes done here are:
- Isolate a basic activation test as non-tentative.
- Replace an existing wpt with a chained setTimeout test.
- Isolate tests for same/cross-origin consumption behavior.
- Clarify tests for same/cross-origin navigation behavior.

Change-Id: I0a7e6d87fc8ed088cd162bbaa8584e8ea7710239
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2110685Reviewed-by: Navid Zolghadr <nzolghadr@chromium.org>
Commit-Queue: Mustaq Ahmed <mustaq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#754529}