Have Frame::animation() return a reference

Source/core/frame/Frame.h

Index: Source/core/frame/Frame.h
diff --git a/Source/core/frame/Frame.h b/Source/core/frame/Frame.h
index bd0dcce7ace83ca7e6fd8996f894864b276b1d8f..7af46d297b0825dadd7c12b58456113f0ba8ecb2 100644
--- a/Source/core/frame/Frame.h
+++ b/Source/core/frame/Frame.h
@@ -101,7 +101,7 @@ namespace WebCore {
         NavigationScheduler* navigationScheduler() const;
         FrameSelection& selection() const;
         FrameTree* tree() const;
-        AnimationController* animation() const;
+        AnimationController& animation() const;
         InputMethodController& inputMethodController() const;
         FetchContext& fetchContext() const { return loader()->fetchContext(); }
         ScriptController* script();
@@ -242,9 +242,9 @@ namespace WebCore {
         return *m_spellChecker;
     }
 
-    inline AnimationController* Frame::animation() const
+    inline AnimationController& Frame::animation() const
     {
-        return m_animationController.get();
+        return *m_animationController;
     }
 
     inline InputMethodController& Frame::inputMethodController() const