Supplement should have a Member to the corresponding Supplementable object (Part 1)

third_party/WebKit/Source/core/dom/CSSSelectorWatch.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 27 matching lines @@
 #include "core/frame/LocalFrame.h"
 #include "core/loader/FrameLoaderClient.h"
 #include "core/style/StyleRareNonInheritedData.h"
 
 namespace blink {
 
 // The address of this string is important; its value is just documentation.
 static const char kSupplementName[] = "CSSSelectorWatch";
 
 CSSSelectorWatch::CSSSelectorWatch(Document& document)
-    : m_document(document)
+    : Supplement<Document>(document)
     , m_callbackSelectorChangeTimer(this, &CSSSelectorWatch::callbackSelectorChangeTimerFired)
     , m_timerExpirations(0)
 {
 }
 
 CSSSelectorWatch& CSSSelectorWatch::from(Document& document)
 {
     CSSSelectorWatch* watch = fromIfExists(document);
     if (!watch) {
         watch = new CSSSelectorWatch(document);
@@ skipping 99 matching lines @@
             continue;
 
         m_watchedCallbackSelectors.append(StyleRule::create(std::move(selectorList), callbackPropertySet));
     }
     document().styleEngine().watchedSelectorsChanged();
 }
 
 DEFINE_TRACE(CSSSelectorWatch)
 {
     visitor->trace(m_watchedCallbackSelectors);
-    visitor->trace(m_document);
     Supplement<Document>::trace(visitor);
 }
 
 } // namespace blink