Pass implementation object to supplemental classes by reference

Source/modules/screen_orientation/ScreenOrientation.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/ScreenOrientation.h"
 
 #include "core/frame/DOMWindow.h"
 #include "core/frame/Frame.h"
 #include "core/frame/Screen.h"
@@ skipping 31 matching lines @@
     for (unsigned i = 0; i < length; ++i) {
         if (orientationMap[i].orientation == orientation)
             return orientationMap[i].name;
     }
     // We do no handle OrientationInvalid and OrientationAny but this is fine because screen.orientation
     // should never return these and WebScreenOrientation does not define those values.
     ASSERT_NOT_REACHED();
     return nullAtom;
 }
 
-ScreenOrientation::ScreenOrientation(Screen* screen)
-    : DOMWindowProperty(screen->frame())
+ScreenOrientation::ScreenOrientation(Screen& screen)
+    : DOMWindowProperty(screen.frame())
 {
 }
 
 const char* ScreenOrientation::supplementName()
 {
     return "ScreenOrientation";
 }
 
-Document* ScreenOrientation::document() const
+Document& ScreenOrientation::document() const
 {
     ASSERT(m_associatedDOMWindow);
-    return m_associatedDOMWindow->document();
+    ASSERT(m_associatedDOMWindow->document());

[dcheng, 2014/02/28 20:54:42]

Please be careful when making these changes. The original code was already
incorrect, but the assumption that DOMWindow/Document can never be null is not
correct. I do not know if there are other such errors in this patch.

[dcheng, 2014/02/28 21:13:41]

Actually, I'm wrong so ignore me for now. Sorry for the noise! I had some extra
changes in my local build.

+    return *m_associatedDOMWindow->document();
 }
 
-ScreenOrientation* ScreenOrientation::from(Screen* screen)
+ScreenOrientation& ScreenOrientation::from(Screen& screen)
 {
     ScreenOrientation* supplement = static_cast<ScreenOrientation*>(Supplement<Screen>::from(screen, supplementName()));
     if (!supplement) {
-        ASSERT(screen);
         supplement = new ScreenOrientation(screen);
         provideTo(screen, supplementName(), adoptPtr(supplement));
     }
-    return supplement;
+    return *supplement;
 }
 
 ScreenOrientation::~ScreenOrientation()
 {
 }
 
-const AtomicString& ScreenOrientation::orientation(Screen* screen)
+const AtomicString& ScreenOrientation::orientation(Screen& screen)
 {
-    ScreenOrientation* screenOrientation = ScreenOrientation::from(screen);
-    ScreenOrientationController* controller = ScreenOrientationController::from(screenOrientation->document());
-    ASSERT(controller);
-    return orientationToString(controller->orientation());
+    ScreenOrientation& screenOrientation = ScreenOrientation::from(screen);
+    ScreenOrientationController& controller = ScreenOrientationController::from(screenOrientation.document());
+    return orientationToString(controller.orientation());
 }
 
-bool ScreenOrientation::lockOrientation(Screen* screen, const Vector<String>& orientations)
+bool ScreenOrientation::lockOrientation(Screen& screen, const Vector<String>& orientations)
 {
     // FIXME: Implement.
     return false;
 }
 
-bool ScreenOrientation::lockOrientation(Screen* screen, const AtomicString& orientation)
+bool ScreenOrientation::lockOrientation(Screen& screen, const AtomicString& orientation)
 {
     // FIXME: Implement.
     return false;
 }
 
-void ScreenOrientation::unlockOrientation(Screen* screen)
+void ScreenOrientation::unlockOrientation(Screen& screen)
 {
     // FIXME: Implement.
 }
 
 } // namespace WebCore