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

mojo/system/message_pipe_endpoint.h

Index: mojo/system/message_pipe_endpoint.h
diff --git a/mojo/system/message_pipe_endpoint.h b/mojo/system/message_pipe_endpoint.h
index a6bf6f9c27f08fb08e1ad5bb6a93cfbe223e1b53..baf5d695be557b3b94f6485784eb92a3ed7f1316 100644
--- a/mojo/system/message_pipe_endpoint.h
+++ b/mojo/system/message_pipe_endpoint.h
@@ -22,7 +22,6 @@
 namespace mojo {
 namespace system {
 
-class Channel;
 class ChannelEndpoint;
 class Waiter;
 
@@ -75,11 +74,9 @@ class MOJO_SYSTEM_IMPL_EXPORT MessagePipeEndpoint {
   // Implementations must override these if they represent a proxy endpoint. An
   // implementation for a local endpoint needs not override these methods, since
   // they should never be called.
-  virtual void Attach(ChannelEndpoint* channel_endpoint,
-                      Channel* channel,
-                      MessageInTransit::EndpointId local_id);
+  virtual void Attach(ChannelEndpoint* channel_endpoint);
   // Returns false if the endpoint should be closed and destroyed, else true.
-  virtual bool Run(MessageInTransit::EndpointId remote_id);
+  virtual bool Run();
   virtual void OnRemove();
 
  protected: