Move core/css/Counter to the oilpan heap.

This moves a few more of the remaining CSSPrimitiveValue [Pass]RefPtr's. While at it I also made
CSSPrimitiveValue and CSValueList use the transition types in our generated code. I will change CSSValue
later when we start changing it's [Pass]RefPtr's.

R=ager@chromium.org, erik.corry@gmail.com, haraken@chromium.org, tkent@chromium.org, vegorov@chromium.org, zerny@chromium.org
BUG=341815

Review URL: https://codereview.chromium.org/163703003

git-svn-id: svn://svn.chromium.org/blink/trunk@167210 bbb929c8-8fbe-4397-9dbb-9b2b20218538