Remove ANIMATION_OWNERSHIP_TRANSFER guard.

ANIMATION_OWNERSHIP_TRANSFER is a temporary macro to change addAnimation() in
both Blink and Chromium. Since Blink synchronized this change, this guard can be removed.

BUG=290217

Review URL: https://codereview.chromium.org/43513002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231013 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231013