Pass implementation object to supplemental classes by reference

Source/modules/donottrack/NavigatorDoNotTrack.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 33 matching lines @@
 
 NavigatorDoNotTrack::~NavigatorDoNotTrack()
 {
 }
 
 const char* NavigatorDoNotTrack::supplementName()
 {
     return "NavigatorDoNotTrack";
 }
 
-NavigatorDoNotTrack* NavigatorDoNotTrack::from(Navigator* navigator)
+NavigatorDoNotTrack& NavigatorDoNotTrack::from(Navigator& navigator)
 {
     NavigatorDoNotTrack* supplement = static_cast<NavigatorDoNotTrack*>(Supplement<Navigator>::from(navigator, supplementName()));
     if (!supplement) {
-        supplement = new NavigatorDoNotTrack(navigator->frame());
+        supplement = new NavigatorDoNotTrack(navigator.frame());
         provideTo(navigator, supplementName(), adoptPtr(supplement));
     }
-    return supplement;
+    return *supplement;
 }
 
-String NavigatorDoNotTrack::doNotTrack(Navigator* navigator)
+String NavigatorDoNotTrack::doNotTrack(Navigator& navigator)
 {
-    return NavigatorDoNotTrack::from(navigator)->doNotTrack();
+    return NavigatorDoNotTrack::from(navigator).doNotTrack();
 }
 
 String NavigatorDoNotTrack::doNotTrack()
 {
     return frame() ? frame()->loader().client()->doNotTrackValue() : String();
 }
 
 } // namespace WebCore