Resolve style in element.animate()

Source/core/animation/KeyframeEffectTest.cpp

Index: Source/core/animation/KeyframeEffectTest.cpp
diff --git a/Source/core/animation/KeyframeEffectTest.cpp b/Source/core/animation/KeyframeEffectTest.cpp
index 5ee2ff3651e3d5a0bd3d71c9e8c1681d9f4e5c1a..01b9074d3c87917be071548bd243e64e88ada7af 100644
--- a/Source/core/animation/KeyframeEffectTest.cpp
+++ b/Source/core/animation/KeyframeEffectTest.cpp
@@ -31,6 +31,7 @@ protected:
         , element(document.createElement("foo", ASSERT_NO_EXCEPTION))
     {
         document.animationClock().resetTimeForTesting(document.timeline().zeroTime());
+        document.documentElement()->appendChild(element);
         EXPECT_EQ(0, document.timeline().currentTime());
     }