[cookie wpt] make tests more reliable
Let's add the listener before setting the src.
Change-Id: I63f7507394301aeac86370331d03651ff1e62c16
Fixed: 352081166
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5709008
Reviewed-by: Dylan Cutler dylancutler@google.com
Auto-Submit: Ari Chivukula arichiv@chromium.org
Commit-Queue: Ari Chivukula arichiv@chromium.org
Cr-Commit-Position: refs/heads/main@{#1327750}