Web Animations: Coalesce constructors where possible.

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 18 matching lines @@
  */
 
 // http://www.w3.org/TR/web-animations/#the-animatable-interface
 // http://www.w3.org/TR/web-animations/#extensions-to-the-element-interface
 
 // TODO(dstockwell): This should be an Animatable interface, where Element
 // implements Animatable. The interface also has several changes:
 // https://w3c.github.io/web-animations/#the-animatable-interface
 
 partial interface Element {
-    // FIXME: Union types with dictionary type members doesn't work (yet).
-    // Animation animate((sequence<Dictionary> or Dictionary)? effect, optional (double or KeyframeEffectOptions) timing);
-    [CallWith=ScriptState, Measure, RaisesException] Animation animate((sequence<Dictionary> or Dictionary)? effect, optional double timing);
-    [CallWith=ScriptState, Measure, RaisesException] Animation animate((sequence<Dictionary> or Dictionary)? effect, KeyframeEffectOptions timing);
+    [CallWith=ScriptState, Measure, RaisesException] Animation animate((sequence<Dictionary> or Dictionary)? effect, optional (unrestricted double or KeyframeEffectOptions) options);
     [RuntimeEnabled=WebAnimationsAPI] sequence<Animation> getAnimations();
 };