Mark http/tests/inspector/appcache/appcache-swap.html as Timeout

TBR=tdanderson
BUG=268111

Review URL: https://codereview.chromium.org/132193007

git-svn-id: svn://svn.chromium.org/blink/trunk@164987 bbb929c8-8fbe-4397-9dbb-9b2b20218538