Use a new Supplement constructor for Supplement<Document> (Part 1)

third_party/WebKit/Source/core/paint/PaintTiming.h

Index: third_party/WebKit/Source/core/paint/PaintTiming.h
diff --git a/third_party/WebKit/Source/core/paint/PaintTiming.h b/third_party/WebKit/Source/core/paint/PaintTiming.h
index 336e8cacad5cd3c060bae413375f939ce0029660..878401ebe7ff4e011ffa582adef576e8eba9f9b4 100644
--- a/third_party/WebKit/Source/core/paint/PaintTiming.h
+++ b/third_party/WebKit/Source/core/paint/PaintTiming.h
@@ -78,7 +78,6 @@ class CORE_EXPORT PaintTiming final
     return m_firstMeaningfulPaintCandidate;
   }
 
-  Document* document() { return m_document.get(); }
   FirstMeaningfulPaintDetector& firstMeaningfulPaintDetector() {
     return *m_fmpDetector;
   }
@@ -109,7 +108,6 @@ class CORE_EXPORT PaintTiming final
   double m_firstMeaningfulPaint = 0.0;
   double m_firstMeaningfulPaintCandidate = 0.0;
 
-  Member<Document> m_document;
   Member<FirstMeaningfulPaintDetector> m_fmpDetector;
 };