Fix wpt flaky tests
Add missing await and change has() to hasOwnProperty().
Change-Id: Ifba707f18b4e8082af2ffb8809d4d959a14f1ca5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5980292
Reviewed-by: Kentaro Hara haraken@chromium.org
Commit-Queue: Tianyang Xu xtlsheep@google.com
Reviewed-by: mmenke mmenke@chromium.org
Cr-Commit-Position: refs/heads/main@{#1378513}