Mojo: Make MessagePipe::ConvertLocalToProxy() create the ChannelEndpoint.

mojo/system/message_pipe_dispatcher.cc

Index: mojo/system/message_pipe_dispatcher.cc
diff --git a/mojo/system/message_pipe_dispatcher.cc b/mojo/system/message_pipe_dispatcher.cc
index c515a00067f8c551b80f906ffa26610f7cfd30bb..85c0d38b6cfc92f871fa05e7c4d83f134a326f07 100644
--- a/mojo/system/message_pipe_dispatcher.cc
+++ b/mojo/system/message_pipe_dispatcher.cc
@@ -247,12 +247,10 @@ bool MessagePipeDispatcher::EndSerializeAndCloseImplNoLock(
     embedder::PlatformHandleVector* /*platform_handles*/) {
   DCHECK(HasOneRef());  // Only one ref => no need to take the lock.
 
-  // Convert the local endpoint to a proxy endpoint (moving the message queue).
-  message_pipe_->ConvertLocalToProxy(port_);
-
-  // Attach the new proxy endpoint to the channel.
-  MessageInTransit::EndpointId endpoint_id = channel->AttachEndpoint(
-      make_scoped_refptr(new ChannelEndpoint(message_pipe_.get(), port_)));
+  // Convert the local endpoint to a proxy endpoint (moving the message queue)
+  // and attach it to the channel.
+  MessageInTransit::EndpointId endpoint_id =
+      channel->AttachEndpoint(message_pipe_->ConvertLocalToProxy(port_));
   // Note: It's okay to get an endpoint ID of |kInvalidEndpointId|. (It's
   // possible that the other endpoint -- the one that we're not sending -- was
   // closed in the intervening time.) In that case, we need to deserialize a