Pass implementation object to supplemental classes by reference

Source/modules/screen_orientation/ScreenOrientationController.cpp

 // Copyright 2014 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.
 
 #include "config.h"
 #include "modules/screen_orientation/ScreenOrientationController.h"
 
 #include "core/dom/Document.h"
 #include "core/events/Event.h"
 #include "core/frame/DOMWindow.h"
 #include "core/frame/Screen.h"
 #include "modules/screen_orientation/ScreenOrientationDispatcher.h"
 
 namespace WebCore {
 
 ScreenOrientationController::~ScreenOrientationController()
 {
     ScreenOrientationDispatcher::instance().removeController(this);
 }
 
-ScreenOrientationController* ScreenOrientationController::from(Document* document)
+ScreenOrientationController& ScreenOrientationController::from(Document& document)
 {
     ScreenOrientationController* controller = static_cast<ScreenOrientationController*>(DocumentSupplement::from(document, supplementName()));
     if (!controller) {
-        controller = new ScreenOrientationController(*document);
+        controller = new ScreenOrientationController(document);
         DocumentSupplement::provideTo(document, supplementName(), adoptPtr(controller));
     }
-    return controller;
+    return *controller;
 }
 
 ScreenOrientationController::ScreenOrientationController(Document& document)
     : m_document(document)
     , m_orientation(blink::WebScreenOrientationPortraitPrimary)
 {
     // FIXME: We should listen for screen orientation change events only when the page is visible.
     ScreenOrientationDispatcher::instance().addController(this);
 }
 
@@ skipping 13 matching lines @@
 void ScreenOrientationController::didChangeScreenOrientation(blink::WebScreenOrientation orientation)
 {
     if (orientation == m_orientation)
         return;
 
     m_orientation = orientation;
     dispatchOrientationChangeEvent();
 }
 
 } // namespace WebCore