--- a/dom/animation/AnimationPlayer.h
+++ b/dom/animation/AnimationPlayer.h
@@ -113,24 +113,23 @@ public:
   // is running and has source content to sample).
   void ComposeStyle(nsRefPtr<css::AnimValuesStyleRule>& aStyleRule,
                     nsCSSPropertySet& aSetProperties,
                     bool& aNeedsRefreshes);
 
   // The beginning of the delay period.
   Nullable<TimeDuration> mStartTime; // Timeline timescale
 
-  nsRefPtr<AnimationTimeline> mTimeline;
-  nsRefPtr<Animation> mSource;
-
 protected:
   void FlushStyle() const;
   void MaybePostRestyle() const;
   StickyTimeDuration SourceContentEnd() const;
 
+  nsRefPtr<AnimationTimeline> mTimeline;
+  nsRefPtr<Animation> mSource;
   Nullable<TimeDuration> mHoldTime;  // Player timescale
   bool mIsPaused;
   bool mIsRunningOnCompositor;
 };
 
 } // namespace dom
 
 class CSSAnimationPlayer MOZ_FINAL : public dom::AnimationPlayer