Remove unneeded display() calls from css3/filters tests

These appear to not be necessary for these tests.

BUG=345027

Review URL: https://codereview.chromium.org/197753010

git-svn-id: svn://svn.chromium.org/blink/trunk@169172 bbb929c8-8fbe-4397-9dbb-9b2b20218538