Web Animations CSS: Start running animations on the compositor

Source/core/animation/css/CSSAnimations.h

Index: Source/core/animation/css/CSSAnimations.h
diff --git a/Source/core/animation/css/CSSAnimations.h b/Source/core/animation/css/CSSAnimations.h
index b0b7e2a11eec1cfd3ab7f2cf57cf107fc1c9ceda..b3b030f44757e514139eb8be666b6da1b677695b 100644
--- a/Source/core/animation/css/CSSAnimations.h
+++ b/Source/core/animation/css/CSSAnimations.h
@@ -164,6 +164,9 @@ public:
     void maybeApplyPendingUpdate(Element*);
     bool isEmpty() const { return m_animations.isEmpty() && m_transitions.isEmpty() && !m_pendingUpdate; }
     void cancel();
+
+    bool hasPendingCandidateWhichShouldComposite(bool renderViewInCompositingMode) const;
+
 private:
     // Note that a single animation name may map to multiple players due to
     // the way in which we split up animations with incomplete keyframes.