Remove PageVisibilityObserver contextDestroyed() notifications.

third_party/WebKit/Source/modules/presentation/PresentationAvailability.h

 // Copyright 2015 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.
 
 #ifndef PresentationAvailability_h
 #define PresentationAvailability_h
 
 #include "bindings/core/v8/ActiveScriptWrappable.h"
 #include "core/dom/SuspendableObject.h"
 #include "core/events/EventTarget.h"
@@ skipping 35 matching lines @@
   void availabilityChanged(bool) override;
   const WebURL url() const override;
 
   // ScriptWrappable implementation.
   bool hasPendingActivity() const final;
 
   // SuspendableObject implementation.
   void suspend() override;
   void resume() override;
   void contextDestroyed(ExecutionContext*) override;
-  void contextDestroyed(Page*) override;
 
   // PageVisibilityObserver implementation.
   void pageVisibilityChanged() override;
 
   bool value() const;
 
   DEFINE_ATTRIBUTE_EVENT_LISTENER(change);
 
   DECLARE_VIRTUAL_TRACE();
 
@@ skipping 19 matching lines @@
   void updateListening();
 
   const KURL m_url;
   bool m_value;
   State m_state;
 };
 
 }  // namespace blink
 
 #endif  // PresentationAvailability_h