Web Animations: Update naming to reflect spec changes

Source/core/animation/AnimationTimingProperties.idl

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// https://w3c.github.io/web-animations/#the-animationeffecttimingproperties-dictionary
-
-// TODO(dstockwell): Rename this to AnimationEffectTimingProperties.
-dictionary AnimationTimingProperties {
-    double                             delay = 0;
-    double                             endDelay = 0;
-    // TODO(dstockwell): The fill type should be FillMode.
-    DOMString                          fill = "auto";
-    double                             iterationStart = 0.0;
-    unrestricted double                iterations = 1.0;
-    (unrestricted double or DOMString) duration = "auto";
-    // TODO(dstockwell): There is no playbackRate member in the spec.
-    double                             playbackRate = 1.0;
-    // TODO(dstockwell): The direction type should be PlaybackDirection.
-    DOMString                          direction = "normal";
-    DOMString                          easing = "linear";
-};