[cc] Use base ptr types for cc's CSS animation classes

Rerelanding https://codereview.chromium.org/11085029/

BUG=154451


Review URL: https://chromiumcodereview.appspot.com/11091057

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@161488 0039d316-1c4b-4281-b951-d872f2087c98
30 files changed