Revert 159836 "DEFINE_CSS_VALUE_TYPE_CASTS starts to use DEFINE_..."

BUG=308594

> DEFINE_CSS_VALUE_TYPE_CASTS starts to use DEFINE_TYPE_CASTS
>
> DEFINE_CSS_VALUE_TYPE_CASTS starts to use DEFINE_TYPE_CASTS so that it is more flexible. Under this change, unusual CSS child values will be able to use the DEFINE_CSS_VALUE_TYPE_CASTS as well.
>
> BUG=N/A
>
> Review URL: https://codereview.chromium.org/26145005

TBR=gyuyoung.kim@samsung.com

Review URL: https://codereview.chromium.org/27498003

git-svn-id: svn://svn.chromium.org/blink/trunk@159885 bbb929c8-8fbe-4397-9dbb-9b2b20218538