Implement DocumentTimeline constructor

third_party/WebKit/Source/core/animation/DocumentTimeline.h

Index: third_party/WebKit/Source/core/animation/DocumentTimeline.h
diff --git a/third_party/WebKit/Source/core/animation/DocumentTimeline.h b/third_party/WebKit/Source/core/animation/DocumentTimeline.h
index 59f41e35329a3bc4fadd4c77fc3df2232d42efc0..fb7bc9dcc212b795c1da7fa5b1701423695da0f1 100644
--- a/third_party/WebKit/Source/core/animation/DocumentTimeline.h
+++ b/third_party/WebKit/Source/core/animation/DocumentTimeline.h
@@ -50,6 +50,7 @@ namespace blink {
 class Animation;
 class AnimationEffectReadOnly;
 class Document;
+class DocumentTimelineOptions;
 
 // DocumentTimeline is constructed and owned by Document, and tied to its
 // lifecycle.
@@ -66,7 +67,13 @@ class CORE_EXPORT DocumentTimeline : public AnimationTimeline {
     DEFINE_INLINE_VIRTUAL_TRACE() {}
   };
 
-  static DocumentTimeline* Create(Document*, PlatformTiming* = nullptr);
+  static DocumentTimeline* Create(Document*,
+                                  double origin_time = 0.0,

[alancutter (OOO until 2018), 2017/06/29 03:16:18]

Let's use origin_time_in_seconds here.

+                                  PlatformTiming* = nullptr);
+
+  // Web Animations API IDL constructor
+  static DocumentTimeline* Create(ExecutionContext*,
+                                  const DocumentTimelineOptions&);
 
   virtual ~DocumentTimeline() {}
 
@@ -112,11 +119,11 @@ class CORE_EXPORT DocumentTimeline : public AnimationTimeline {
 
   DECLARE_VIRTUAL_TRACE();
 
- protected:
-  DocumentTimeline(Document*, PlatformTiming*);
-
  private:
+  DocumentTimeline(Document*, double origin_time, PlatformTiming*);
+
   Member<Document> document_;
+  double origin_time_;
   double zero_time_;
   bool zero_time_initialized_;
   unsigned outdated_animation_count_;