Fix the insecure-css-resources.html layout test.

CSS content is considered as active content, and therefore "runs" instead
of "displays". Change this in the test expectations.

TBR=dcheng@chromium.org, bashi@chromium.org
NOTRY=true
BUG=377864

Review URL: https://codereview.chromium.org/317173002

git-svn-id: svn://svn.chromium.org/blink/trunk@175570 bbb929c8-8fbe-4397-9dbb-9b2b20218538