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

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PaintTiming_h
 #define PaintTiming_h
 
 #include "core/dom/Document.h"
 #include "core/paint/FirstMeaningfulPaintDetector.h"
 #include "platform/Supplementable.h"
@@ skipping 60 matching lines @@
   double firstMeaningfulPaint() const { return m_firstMeaningfulPaint; }
 
   // firstMeaningfulPaintCandidate indicates the first time we considered a
   // paint to qualify as the potentially first meaningful paint. Unlike
   // firstMeaningfulPaint, this signal is available in real time, but it may be
   // an optimistic (i.e., too early) estimate.
   double firstMeaningfulPaintCandidate() const {
     return m_firstMeaningfulPaintCandidate;
   }
 
-  Document* document() { return m_document.get(); }
   FirstMeaningfulPaintDetector& firstMeaningfulPaintDetector() {
     return *m_fmpDetector;
   }
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   explicit PaintTiming(Document&);
   LocalFrame* frame() const;
   void notifyPaintTimingChanged();
@@ skipping 10 matching lines @@
   // time has not yet been recorded.
   void setFirstContentfulPaint(double stamp);
 
   double m_firstPaint = 0.0;
   double m_firstTextPaint = 0.0;
   double m_firstImagePaint = 0.0;
   double m_firstContentfulPaint = 0.0;
   double m_firstMeaningfulPaint = 0.0;
   double m_firstMeaningfulPaintCandidate = 0.0;
 
-  Member<Document> m_document;
   Member<FirstMeaningfulPaintDetector> m_fmpDetector;
 };
 
 }  // namespace blink
 
 #endif