Add deletion observer to P2PSocketDispatcher.

content/renderer/p2p/socket_dispatcher.h

 // Copyright (c) 2012 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.
 
 // P2PSocketDispatcher is a per-renderer object that dispatchers all
 // P2P messages received from the browser and relays all P2P messages
 // sent to the browser. P2PSocketClient instances register themselves
 // with the dispatcher using RegisterClient() and UnregisterClient().
 //
 // Relationship of classes.
@@ skipping 34 matching lines @@
 
 namespace webkit_glue {
 class NetworkListObserver;
 }  // webkit_glue
 
 namespace content {
 
 class P2PHostAddressRequest;
 class P2PSocketClient;
 
+// Callback interface that allows the implementor to be notified before a
+// P2PSocketDispatcher is destroyed.
+// P2PSocketDispatcher requires that all NetworkListObservers are
+// unregistered when SocketDispatcherGone is called.
+class P2PSocketDispatcherDestructionObserver {
+ public:
+  virtual void OnSocketDispatcherDestroyed() = 0;
+
+ protected:
+  virtual ~P2PSocketDispatcherDestructionObserver() {}
+};
+
 class CONTENT_EXPORT P2PSocketDispatcher : public content::RenderViewObserver {
  public:
   explicit P2PSocketDispatcher(RenderViewImpl* render_view);
   virtual ~P2PSocketDispatcher();
 
   // Add a new network list observer. Each observer is called
   // immidiately after it is registered and then later whenever
   // network configuration changes. Can be called on any thread. The
   // observer is always called on the thread it was added.
   void AddNetworkListObserver(
       webkit_glue::NetworkListObserver* network_list_observer);
 
   // Removes network list observer. Must be called on the thread on
   // which the observer was added.
   void RemoveNetworkListObserver(
       webkit_glue::NetworkListObserver* network_list_observer);
 
+  void AddDestructionObserver(P2PSocketDispatcherDestructionObserver* observer);
+  void RemoveDestructionObserver(
+      P2PSocketDispatcherDestructionObserver* observer);
+
   // RenderViewObserver overrides.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
  private:
   friend class P2PHostAddressRequest;
   friend class P2PSocketClient;
   class AsyncMessageSender;
 
   base::MessageLoopProxy* message_loop();
 
@@ skipping 22 matching lines @@
   IDMap<P2PSocketClient> clients_;
 
   IDMap<P2PHostAddressRequest> host_address_requests_;
 
   bool network_notifications_started_;
   scoped_refptr<ObserverListThreadSafe<webkit_glue::NetworkListObserver> >
       network_list_observers_;
 
   scoped_refptr<AsyncMessageSender> async_message_sender_;
 
+  ObserverList<P2PSocketDispatcherDestructionObserver> destruction_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(P2PSocketDispatcher);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_P2P_SOCKET_DISPATCHER_H_