Fix DOMWindow::isCurrentlyDisplayedInFrame to return false when detached

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/LocalFrame.h"
 #include "core/frame/Screen.h"
@@ skipping 81 matching lines @@
         blink::Platform::current()->unlockOrientation();
     else
         blink::Platform::current()->lockOrientation(m_lockedOrientations);
 }
 
 const char* ScreenOrientation::supplementName()
 {
     return "ScreenOrientation";
 }
 
-Document& ScreenOrientation::document() const
+Document* ScreenOrientation::document() const
 {
-    ASSERT(m_associatedDOMWindow);
+    if (!m_associatedDOMWindow || !m_associatedDOMWindow->isCurrentlyDisplayedInFrame())
+        return 0;
     ASSERT(m_associatedDOMWindow->document());
-    return *m_associatedDOMWindow->document();
+    return m_associatedDOMWindow->document();
 }
 
 ScreenOrientation& ScreenOrientation::from(Screen& screen)
 {
     ScreenOrientation* supplement = static_cast<ScreenOrientation*>(Supplement<Screen>::from(screen, supplementName()));
     if (!supplement) {
         supplement = new ScreenOrientation(screen);
         provideTo(screen, supplementName(), adoptPtr(supplement));
     }
     return *supplement;
 }
 
 ScreenOrientation::~ScreenOrientation()
 {
 }
 
 const AtomicString& ScreenOrientation::orientation(Screen& screen)
 {
     ScreenOrientation& screenOrientation = ScreenOrientation::from(screen);
-    ScreenOrientationController& controller = ScreenOrientationController::from(screenOrientation.document());
+    if (!screenOrientation.document())
+        return emptyAtom;
+    ScreenOrientationController& controller = ScreenOrientationController::from(*screenOrientation.document());
     return orientationToString(controller.orientation());
 }
 
 bool ScreenOrientation::lockOrientation(Screen& screen, const Vector<String>& orientationsVector)
 {
     blink::WebScreenOrientations orientations = 0;
     for (size_t i = 0; i < orientationsVector.size(); ++i) {
         blink::WebScreenOrientations currentOrientation = stringToOrientations(AtomicString(orientationsVector[i]));
         if (!currentOrientation)
             return false;
@@ skipping 13 matching lines @@
     ScreenOrientation::from(screen).lockOrientationAsync(orientations);
     return true;
 }
 
 void ScreenOrientation::unlockOrientation(Screen& screen)
 {
     ScreenOrientation::from(screen).lockOrientationAsync(WebScreenOrientationDefault);
 }
 
 } // namespace WebCore