Pass implementation object to supplemental classes by reference

Source/modules/webmidi/NavigatorWebMIDI.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 35 matching lines @@
 
 NavigatorWebMIDI::~NavigatorWebMIDI()
 {
 }
 
 const char* NavigatorWebMIDI::supplementName()
 {
     return "NavigatorWebMIDI";
 }
 
-NavigatorWebMIDI* NavigatorWebMIDI::from(Navigator* navigator)
+NavigatorWebMIDI& NavigatorWebMIDI::from(Navigator& navigator)
 {
     NavigatorWebMIDI* supplement = static_cast<NavigatorWebMIDI*>(Supplement<Navigator>::from(navigator, supplementName()));
     if (!supplement) {
-        supplement = new NavigatorWebMIDI(navigator->frame());
+        supplement = new NavigatorWebMIDI(navigator.frame());
         provideTo(navigator, supplementName(), adoptPtr(supplement));
     }
-    return supplement;
+    return *supplement;
 }
 
-PassRefPtrWillBeRawPtr<MIDIAccessPromise> NavigatorWebMIDI::requestMIDIAccess(Navigator* navigator, const Dictionary& options)
+PassRefPtrWillBeRawPtr<MIDIAccessPromise> NavigatorWebMIDI::requestMIDIAccess(Navigator& navigator, const Dictionary& options)
 {
-    return NavigatorWebMIDI::from(navigator)->requestMIDIAccess(options);
+    return NavigatorWebMIDI::from(navigator).requestMIDIAccess(options);
 }
 
 PassRefPtrWillBeRawPtr<MIDIAccessPromise> NavigatorWebMIDI::requestMIDIAccess(const Dictionary& options)
 {
     if (!frame())
         return 0;
 
     ExecutionContext* context = frame()->document();
     ASSERT(context);
 
     return MIDIAccessPromise::create(context, options);
 }
 
 } // namespace WebCore