Web Animations: Update naming to reflect spec changes

Source/core/animation/KeyframeEffect.idl

Index: Source/core/animation/KeyframeEffect.idl
diff --git a/Source/core/animation/Animation.idl b/Source/core/animation/KeyframeEffect.idl
similarity index 84%
copy from Source/core/animation/Animation.idl
copy to Source/core/animation/KeyframeEffect.idl
index 2da00b3bac00cb93fe8f2ab90e9bb0660c6eb868..0235507d149325283a9c79cc9ffcae328af77641 100644
--- a/Source/core/animation/Animation.idl
+++ b/Source/core/animation/KeyframeEffect.idl
@@ -28,18 +28,14 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// http://www.w3.org/TR/web-animations/#the-animation-interface
-
-// TODO(dstockwell): This interface has been renamed to KeyframeEffect in the
-// latest spec:
 // https://w3c.github.io/web-animations/#the-keyframeeffect-interfaces
 
 [
-    // FIXME: the third argument should be "optional (unrestricted double or AnimationTimingProperties) timing".
+    // TODO(dstockwell): the third argument should be "optional (unrestricted double or KeyframeEffectOptions) timing".
     Constructor(Element? target, sequence<Dictionary> keyframes, optional unrestricted double timing),
-    Constructor(Element? target, sequence<Dictionary> keyframes, AnimationTimingProperties timing),
+    Constructor(Element? target, sequence<Dictionary> keyframes, KeyframeEffectOptions timing),
     RaisesException=Constructor,
     RuntimeEnabled=WebAnimationsAPI,
     TypeChecking=Interface,
-] interface Animation : AnimationNode {
+] interface KeyframeEffect : AnimationEffectReadOnly {
 };