Blink gardening: dynamic-stylesheet-loading.html gets timeout

TBR=enne@chromium.org
BUG=N/A
NOTRY=true

Review URL: https://codereview.chromium.org/26660002

git-svn-id: svn://svn.chromium.org/blink/trunk@159206 bbb929c8-8fbe-4397-9dbb-9b2b20218538