Fix animations not starting on detached elements

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 3cecee2be8b4fbdafda459a24b8696c3f28c88e5..adca3d92699d09a15800be89f0c1de02e59bdcc7 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -472,6 +472,11 @@ void Internals::pauseAnimations(double pauseTime, ExceptionState& exceptionState
     frame()->document()->timeline().pauseAnimationsForTesting(pauseTime);
 }
 
+bool Internals::isCompositedAnimation(Animation* animation)
+{
+    return animation->hasActiveAnimationsOnCompositor();
+}
+
 void Internals::advanceTimeForImage(Element* image, double deltaTimeInSeconds, ExceptionState& exceptionState)
 {
     ASSERT(image);