Make BrowserMessageFilter not derive from IPC::ChannelProxy::MessageFilter. This allows us to hide …

ipc/ipc_channel_proxy.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.
 
 #ifndef IPC_IPC_CHANNEL_PROXY_H_
 #define IPC_IPC_CHANNEL_PROXY_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
@@ skipping 36 matching lines @@
 // the consumer of IPC::ChannelProxy the ability to respond to incoming
 // messages on this background thread instead of on their own thread, which may
 // be bogged down with other processing.  The result can be greatly improved
 // latency for messages that can be handled on a background thread.
 //
 // The consumer of IPC::ChannelProxy is responsible for allocating the Thread
 // instance where the IPC::Channel will be created and operated.
 //
 class IPC_EXPORT ChannelProxy : public Sender, public base::NonThreadSafe {
  public:
-  struct MessageFilterTraits;
 
   // A class that receives messages on the thread where the IPC channel is
   // running.  It can choose to prevent the default action for an IPC message.
   class IPC_EXPORT MessageFilter
-      : public base::RefCountedThreadSafe<MessageFilter, MessageFilterTraits> {
+      : public base::RefCountedThreadSafe<MessageFilter> {
    public:
     MessageFilter();
 
     // Called on the background thread to provide the filter with access to the
     // channel.  Called when the IPC channel is initialized or when AddFilter
     // is called if the channel is already initialized.
     virtual void OnFilterAdded(Channel* channel);
 
     // Called on the background thread when the filter has been removed from
     // the ChannelProxy and when the Channel is closing.  After a filter is
     // removed, it will not be called again.
     virtual void OnFilterRemoved();
 
     // Called to inform the filter that the IPC channel is connected and we
     // have received the internal Hello message from the peer.
     virtual void OnChannelConnected(int32 peer_pid);
 
     // Called when there is an error on the channel, typically that the channel
     // has been closed.
     virtual void OnChannelError();
 
     // Called to inform the filter that the IPC channel will be destroyed.
     // OnFilterRemoved is called immediately after this.
     virtual void OnChannelClosing();
 
     // Return true to indicate that the message was handled, or false to let
     // the message be handled in the default way.
     virtual bool OnMessageReceived(const Message& message);
 
-    // Called when the message filter is about to be deleted.  This gives
-    // derived classes the option of controlling which thread they're deleted
-    // on etc.
-    virtual void OnDestruct() const;
-
    protected:
     virtual ~MessageFilter();
 
    private:
-    friend class base::RefCountedThreadSafe<MessageFilter,
-                                            MessageFilterTraits>;
+    friend class base::RefCountedThreadSafe<MessageFilter>;
   };
 
-  struct MessageFilterTraits {
-    static void Destruct(const MessageFilter* filter) {
-      filter->OnDestruct();
-    }
-  };
-
-
   // Interface for a filter to be imposed on outgoing messages which can
   // re-write the message.  Used mainly for testing.
   class OutgoingMessageFilter {
    public:
     // Returns a re-written message, freeing the original, or simply the
     // original unchanged if no rewrite indicated.
     virtual Message *Rewrite(Message *message) = 0;
   };
 
   // Initializes a channel proxy.  The channel_handle and mode parameters are
@@ skipping 162 matching lines @@
 
   OutgoingMessageFilter* outgoing_message_filter_;
 
   // Whether the channel has been initialized.
   bool did_init_;
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_PROXY_H_