Mojo: Remove knowledge of Channel, etc. from ProxyMessagePipeEndpoint.

mojo/system/message_pipe.h

Index: mojo/system/message_pipe.h
diff --git a/mojo/system/message_pipe.h b/mojo/system/message_pipe.h
index 3bc57a55110e898fe50bf60cd1bfda6fdcd10324..f732f978e358dedd2d6cb4d7523899513303f49a 100644
--- a/mojo/system/message_pipe.h
+++ b/mojo/system/message_pipe.h
@@ -25,7 +25,6 @@
 namespace mojo {
 namespace system {
 
-class Channel;
 class ChannelEndpoint;
 class Waiter;
 
@@ -96,11 +95,8 @@ class MOJO_SYSTEM_IMPL_EXPORT MessagePipe
                             scoped_ptr<MessageInTransit> message);
 
   // These are used by |Channel|.
-  bool Attach(unsigned port,
-              ChannelEndpoint* channel_endpoint,
-              Channel* channel,
-              MessageInTransit::EndpointId local_id);
-  void Run(unsigned port, MessageInTransit::EndpointId remote_id);
+  bool Attach(unsigned port, ChannelEndpoint* channel_endpoint);
+  void Run(unsigned port);
   void OnRemove(unsigned port);
 
  private: