Remove AnimationEffectTimingProperties playbackRate

third_party/WebKit/Source/core/animation/AnimationEffectTimingProperties.idl

 // Copyright 2016 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
 
 enum FillMode { "none", "forwards", "backwards", "both", "auto" };
 enum PlaybackDirection { "normal", "reverse", "alternate", "alternate-reverse" };
 
 dictionary AnimationEffectTimingProperties {
     double                             delay = 0;
     double                             endDelay = 0;
     FillMode                           fill = "auto";
     double                             iterationStart = 0.0;
     unrestricted double                iterations = 1.0;
     (unrestricted double or DOMString) duration = "auto";
-    // TODO(alancutter): Remove playbackRate.
-    double                             playbackRate = 1.0;
     PlaybackDirection                  direction = "normal";
     DOMString                          easing = "linear";
 };