Revert "FORK: Disable WebAnimationsCSS"

Bug: 12393371

This reverts commit d27dc098443975487354b187165a69ee95b04be4.
The proper fix for this change
 http://src.chromium.org/viewvc/blink?view=rev&rev=165030
is now pushed to internal M33 tree.

Change-Id: Ia9d47a72cb3f7c1bd0f453a9cc3f4f998826792b
1 file changed