Remove PageVisibilityObserver contextDestroyed() notifications.

third_party/WebKit/Source/modules/presentation/PresentationAvailability.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 "modules/presentation/PresentationAvailability.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/Document.h"
 #include "core/events/Event.h"
 #include "core/frame/UseCounter.h"
@@ skipping 80 matching lines @@
 }
 
 void PresentationAvailability::suspend() {
   setState(State::Suspended);
 }
 
 void PresentationAvailability::contextDestroyed(ExecutionContext*) {
   setState(State::Inactive);
 }
 
-void PresentationAvailability::contextDestroyed(Page*) {}
-
 void PresentationAvailability::pageVisibilityChanged() {
   if (m_state == State::Inactive)
     return;
   updateListening();
 }
 
 void PresentationAvailability::setState(State state) {
   m_state = state;
   updateListening();
 }
@@ skipping 19 matching lines @@
   return m_value;
 }
 
 DEFINE_TRACE(PresentationAvailability) {
   EventTargetWithInlineData::trace(visitor);
   PageVisibilityObserver::trace(visitor);
   SuspendableObject::trace(visitor);
 }
 
 }  // namespace blink