Remove PageVisibilityObserver contextDestroyed() notifications.

third_party/WebKit/Source/modules/nfc/NFC.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 NFC_h
 #define NFC_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "bindings/modules/v8/StringOrArrayBufferOrNFCMessage.h"
@@ skipping 22 matching lines @@
 
  public:
   static NFC* create(LocalFrame*);
 
   virtual ~NFC();
 
   void dispose();
 
   // ContextLifecycleObserver overrides.
   void contextDestroyed(ExecutionContext*) override;
-  void contextDestroyed(Page*) override;
 
   // Pushes NFCPushMessage asynchronously to NFC tag / peer.
   ScriptPromise push(ScriptState*,
                      const NFCPushMessage&,
                      const NFCPushOptions&);
 
   // Cancels ongoing push operation.
   ScriptPromise cancelPush(ScriptState*, const String&);
 
   // Starts watching for NFC messages that match NFCWatchOptions criteria.
@@ skipping 33 matching lines @@
   device::nfc::mojom::blink::NFCPtr m_nfc;
   mojo::Binding<device::nfc::mojom::blink::NFCClient> m_client;
   HeapHashSet<Member<ScriptPromiseResolver>> m_requests;
   using WatchCallbacksMap = HeapHashMap<uint32_t, Member<MessageCallback>>;
   WatchCallbacksMap m_callbacks;
 };
 
 }  // namespace blink
 
 #endif  // NFC_h