RefCounted types should not have public destructors, delegate cleanup

ipc/ipc_channel.h

Index: ipc/ipc_channel.h
diff --git a/ipc/ipc_channel.h b/ipc/ipc_channel.h
index 2aeca1fceda3a79ee34e080fb60e2487e404203e..b2742e604fb2006d68fa019667f910ac6d999641 100644
--- a/ipc/ipc_channel.h
+++ b/ipc/ipc_channel.h
@@ -40,8 +40,6 @@ class IPC_EXPORT Channel : public Message::Sender {
   // Implemented by consumers of a Channel to receive messages.
   class IPC_EXPORT Listener {
    public:
-    virtual ~Listener() {}
-
     // Called when a message is received.  Returns true iff the message was
     // handled.
     virtual bool OnMessageReceived(const Message& message) = 0;
@@ -63,6 +61,9 @@ class IPC_EXPORT Channel : public Message::Sender {
     // has an error that causes the listening channel to close.
     virtual void OnChannelListenError() {}
 #endif  // OS_POSIX
+
+   protected:
+    virtual ~Listener() {}
   };
 
   // Flags to test modes