Pass implementation object to supplemental classes by reference

Source/core/dom/DocumentFullscreen.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:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 12 matching lines @@
  * DAMAGE.
  */
 
 #include "config.h"
 #include "core/dom/DocumentFullscreen.h"
 
 #include "core/dom/FullscreenElementStack.h"
 
 namespace WebCore {
 
-bool DocumentFullscreen::webkitIsFullScreen(Document* document)
+bool DocumentFullscreen::webkitIsFullScreen(Document& document)
 {
     if (FullscreenElementStack* fullscreen = FullscreenElementStack::fromIfExists(document))
         return fullscreen->webkitIsFullScreen();
     return false;
 }
 
-bool DocumentFullscreen::webkitFullScreenKeyboardInputAllowed(Document* document)
+bool DocumentFullscreen::webkitFullScreenKeyboardInputAllowed(Document& document)
 {
     if (FullscreenElementStack* fullscreen = FullscreenElementStack::fromIfExists(document))
         return fullscreen->webkitFullScreenKeyboardInputAllowed();
     return false;
 }
 
-Element* DocumentFullscreen::webkitCurrentFullScreenElement(Document* document)
+Element* DocumentFullscreen::webkitCurrentFullScreenElement(Document& document)
 {
     if (FullscreenElementStack* fullscreen = FullscreenElementStack::fromIfExists(document))
         return fullscreen->webkitCurrentFullScreenElement();
     return 0;
 }
 
-void DocumentFullscreen::webkitCancelFullScreen(Document* document)
+void DocumentFullscreen::webkitCancelFullScreen(Document& document)
 {
-    FullscreenElementStack::from(document)->webkitCancelFullScreen();
+    FullscreenElementStack::from(document).webkitCancelFullScreen();
 }
 
-bool DocumentFullscreen::webkitFullscreenEnabled(Document* document)
+bool DocumentFullscreen::webkitFullscreenEnabled(Document& document)
 {
     return FullscreenElementStack::webkitFullscreenEnabled(document);
 }
 
-Element* DocumentFullscreen::webkitFullscreenElement(Document* document)
+Element* DocumentFullscreen::webkitFullscreenElement(Document& document)
 {
     if (FullscreenElementStack* fullscreen = FullscreenElementStack::fromIfExists(document))
         return fullscreen->webkitFullscreenElement();
     return 0;
 }
 
-void DocumentFullscreen::webkitExitFullscreen(Document* document)
+void DocumentFullscreen::webkitExitFullscreen(Document& document)
 {
-    FullscreenElementStack::from(document)->webkitExitFullscreen();
+    FullscreenElementStack::from(document).webkitExitFullscreen();
 }
 
 } // namespace WebCore