Remove tests which only test getPropertyCSSValue

getPropertyCSSValue, CSSValue, etc. are no longer web-exposed and about
to be deleted as soon as tests no longer depend on them.

BUG=428595

Review URL: https://codereview.chromium.org/682833005

git-svn-id: svn://svn.chromium.org/blink/trunk@185089 bbb929c8-8fbe-4397-9dbb-9b2b20218538