Implement new AnimationTimeline superclass

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

Index: third_party/WebKit/Source/core/animation/SuperAnimationTimeline.h
diff --git a/third_party/WebKit/Source/core/animation/SuperAnimationTimeline.h b/third_party/WebKit/Source/core/animation/SuperAnimationTimeline.h
new file mode 100644
index 0000000000000000000000000000000000000000..e582d1e37533f179b8c606651be620c2173380e6
--- /dev/null
+++ b/third_party/WebKit/Source/core/animation/SuperAnimationTimeline.h
@@ -0,0 +1,26 @@
+#ifndef SuperAnimationTimeline_h
+#define SuperAnimationTimeline_h
+
+#include "core/CoreExport.h"
+#include "platform/bindings/ScriptWrappable.h"
+
+namespace blink {
+
+class CORE_EXPORT SuperAnimationTimeline
+    : public GarbageCollectedFinalized<SuperAnimationTimeline>,
+      public ScriptWrappable {
+  DEFINE_WRAPPERTYPEINFO();
+
+ public:
+  virtual ~SuperAnimationTimeline() {}
+
+  virtual double currentTime(bool&) = 0;
+
+  virtual bool IsAnimationTimeline() const { return false; }
+
+  DEFINE_INLINE_VIRTUAL_TRACE() {}
+};
+
+}  // namespace blink
+
+#endif