Remove DOMWindowLifecycleObserver

third_party/WebKit/Source/core/frame/DeviceSingleWindowEventController.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 "core/frame/DeviceSingleWindowEventController.h"
 
 #include "core/dom/Document.h"
 #include "core/events/Event.h"
-#include "core/frame/LocalDOMWindow.h"
 #include "core/page/Page.h"
 
 namespace blink {
 
 DeviceSingleWindowEventController::DeviceSingleWindowEventController(Document& document)
     : PlatformEventController(document.page())
-    , DOMWindowLifecycleObserver(document.domWindow())
     , m_needsCheckingNullEvents(true)
     , m_document(document)
 {
+    document.domWindow()->registerEventListenerObserver(this);
 }
 
 DeviceSingleWindowEventController::~DeviceSingleWindowEventController()
 {
 }
 
 void DeviceSingleWindowEventController::didUpdateData()
 {
     dispatchDeviceEvent(lastEvent());
 }
@@ skipping 36 matching lines @@
 void DeviceSingleWindowEventController::didRemoveAllEventListeners(LocalDOMWindow*)
 {
     stopUpdating();
     m_hasEventListener = false;
 }
 
 DEFINE_TRACE(DeviceSingleWindowEventController)
 {
     visitor->trace(m_document);
     PlatformEventController::trace(visitor);
-    DOMWindowLifecycleObserver::trace(visitor);
 }
 
 } // namespace blink