Fix animations not starting on detached elements

Source/core/testing/Internals.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 91 matching lines @@
     ShadowRoot* shadowRoot(Element* host);
     ShadowRoot* youngestShadowRoot(Element* host);
     ShadowRoot* oldestShadowRoot(Element* host);
     ShadowRoot* youngerShadowRoot(Node* shadow, ExceptionState&);
     String shadowRootType(const Node*, ExceptionState&) const;
     bool hasShadowInsertionPoint(const Node*, ExceptionState&) const;
     bool hasContentElement(const Node*, ExceptionState&) const;
     size_t countElementShadow(const Node*, ExceptionState&) const;
     const AtomicString& shadowPseudoId(Element*);
 
-    // CSS Animation / Transition testing.
+    // Animation testing.
     void pauseAnimations(double pauseTime, ExceptionState&);
+    bool isCompositedAnimation(Animation*);
 
     // Modifies m_desiredFrameStartTime in BitmapImage to advance the next frame time
     // for testing whether animated images work properly.
     void advanceTimeForImage(Element* image, double deltaTimeInSeconds, ExceptionState&);
 
     bool isValidContentSelect(Element* insertionPoint, ExceptionState&);
     Node* treeScopeRootNode(Node*);
     Node* parentTreeScope(Node*);
     bool hasSelectorForIdInShadow(Element* host, const AtomicString& idValue, ExceptionState&);
     bool hasSelectorForClassInShadow(Element* host, const AtomicString& className, ExceptionState&);
@@ skipping 250 matching lines @@
 
     DocumentMarker* markerAt(Node*, const String& markerType, unsigned index, ExceptionState&);
     Member<InternalRuntimeFlags> m_runtimeFlags;
 
     IterationSource* startIteration(ScriptState*, ExceptionState&) override;
 };
 
 } // namespace blink
 
 #endif // Internals_h