Fenced frame: attempt to deflake ancestor-throttle test.
When the test was originally written, the timeout would write "blocked"
to the server after 3 seconds. It was later changed to 1 second. This is
likely not enough time for any loads to happen. This CL changes the
timeout back to 3 seconds to give the frames enough time to fully load.
Bug: 352059339
Change-Id: I379198432abd47236d4697e3071c5c40d8b80849
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5707436
Commit-Queue: Liam Brady lbrady@google.com
Commit-Queue: Andrew Verge averge@chromium.org
Reviewed-by: Andrew Verge averge@chromium.org
Cr-Commit-Position: refs/heads/main@{#1327605}