Web Animations API: Refactor IDL input conversion out of Animation

Source/core/animation/Animation.h

Index: Source/core/animation/Animation.h
diff --git a/Source/core/animation/Animation.h b/Source/core/animation/Animation.h
index f360e3c9a57909c5249bf91080146c5a504681ce..68519aecf81d69ddc9fb47d1fcebcd3f00c50373 100644
--- a/Source/core/animation/Animation.h
+++ b/Source/core/animation/Animation.h
@@ -49,8 +49,7 @@ public:
     static PassRefPtr<Animation> create(PassRefPtr<Element>, PassRefPtrWillBeRawPtr<AnimationEffect>, const Timing&, Priority = DefaultPriority, PassOwnPtr<EventDelegate> = nullptr);
     // Web Animations API Bindings constructors.
     static PassRefPtr<Animation> create(Element*, Vector<Dictionary> keyframeDictionaryVector, Dictionary timingInput);
-    static PassRefPtr<Animation> create(Element*, Vector<Dictionary> keyframeDictionaryVector, double timingInput);
-    static PassRefPtr<Animation> create(Element*, Vector<Dictionary> keyframeDictionaryVector);
+    static PassRefPtr<Animation> create(Element*, Vector<Dictionary> keyframeDictionaryVector, double duration = Timing::initialIterationDuration());
 
     // FIXME: Move all of these setter methods out of Animation,
     // possibly into a new class (TimingInput?).
@@ -97,8 +96,7 @@ private:
     static void populateTiming(Timing&, Dictionary);
     // createUnsafe should only be directly called from tests.
     static PassRefPtr<Animation> createUnsafe(Element*, Vector<Dictionary> keyframeDictionaryVector, Dictionary timingInput);
-    static PassRefPtr<Animation> createUnsafe(Element*, Vector<Dictionary> keyframeDictionaryVector, double timingInput);
-    static PassRefPtr<Animation> createUnsafe(Element*, Vector<Dictionary> keyframeDictionaryVector);
+    static PassRefPtr<Animation> createUnsafe(Element*, Vector<Dictionary> keyframeDictionaryVector, double duration = Timing::initialIterationDuration());
 
     Animation(PassRefPtr<Element>, PassRefPtrWillBeRawPtr<AnimationEffect>, const Timing&, Priority, PassOwnPtr<EventDelegate>);