Remove outdated FIXME

Source/core/layout/LayoutObject.h

Index: Source/core/layout/LayoutObject.h
diff --git a/Source/core/layout/LayoutObject.h b/Source/core/layout/LayoutObject.h
index 1f5e248007293af160a3578f1a3882552a0a4ab1..6061fdb0b6ded46c8c5ab8e53069ae052a0eeb63 100644
--- a/Source/core/layout/LayoutObject.h
+++ b/Source/core/layout/LayoutObject.h
@@ -860,9 +860,7 @@ public:
     // Actually do the paint invalidate of rect r for this object which has been computed in the coordinate space
     // of the GraphicsLayer backing of |paintInvalidationContainer|. Note that this coordinaten space is not the same
     // as the local coordinate space of |paintInvalidationContainer| in the presence of layer squashing.
-    // If |paintInvalidationContainer| is 0, invalidate paints via the view.
-    // FIXME: |paintInvalidationContainer| should never be 0. See crbug.com/363699.
-    void invalidatePaintUsingContainer(const LayoutBoxModelObject* paintInvalidationContainer, const LayoutRect&, PaintInvalidationReason) const;
+    void invalidatePaintUsingContainer(const LayoutBoxModelObject& paintInvalidationContainer, const LayoutRect&, PaintInvalidationReason) const;
 
     // Invalidate the paint of a specific subrectangle within a given object. The rect |r| is in the object's coordinate space.
     void invalidatePaintRectangle(const LayoutRect&) const;
@@ -1229,7 +1227,7 @@ private:
     void setLayoutDidGetCalledSinceLastFrame();
     void clearLayoutDidGetCalledSinceLastFrame() { m_bitfields.setLayoutDidGetCalledSinceLastFrame(false); }
 
-    void invalidatePaintIncludingNonCompositingDescendantsInternal(const LayoutBoxModelObject* repaintContainer);
+    void invalidatePaintIncludingNonCompositingDescendantsInternal(const LayoutBoxModelObject& repaintContainer);
 
     LayoutRect previousSelectionRectForPaintInvalidation() const;
     void setPreviousSelectionRectForPaintInvalidation(const LayoutRect&);