Oilpan: Notify supplements of Page and LocalFrame destruction.

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/frame/DOMWindow.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Screen.h"
 #include "core/page/Page.h"
 #include "platform/LayoutTestSupport.h"
 #include "platform/PlatformScreen.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebScreenOrientationClient.h"
 
 namespace WebCore {
 
 ScreenOrientationController::~ScreenOrientationController()
 {
 }
 
+void ScreenOrientationController::persistentHostHasBeenDestroyed()
+{
+    // Unregister lifecycle observation once page is being torn down.
+    observeContext(0);
+}
+
 void ScreenOrientationController::provideTo(LocalFrame& frame, blink::WebScreenOrientationClient* client)
 {
     ScreenOrientationController* controller = new ScreenOrientationController(frame, client);
     WillBeHeapSupplement<LocalFrame>::provideTo(frame, supplementName(), adoptPtrWillBeNoop(controller));
 }
 
 ScreenOrientationController& ScreenOrientationController::from(LocalFrame& frame)
 {
     return *static_cast<ScreenOrientationController*>(WillBeHeapSupplement<LocalFrame>::from(frame, supplementName()));
 }
@@ skipping 91 matching lines @@
     if (!m_client) {
         // FIXME: temporary until the content layer gets updated.
         blink::Platform::current()->unlockOrientation();
         return;
     }
 
     m_client->unlockOrientation();
 }
 
 } // namespace WebCore