Mark a few more appcache layout tests as slow.
Mark a few more appcache layout tests as slow.

TEST=none
BUG=24182

Review URL: http://codereview.chromium.org/460034

git-svn-id: http://src.chromium.org/svn/trunk/src@33643 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 30fc7dc2e0f4d10978a4c0d7c37313d644fbd3a6
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser