Mojo: Remove DCHECK disallowing passing of a remote message pipe.

mojo/system/message_pipe.cc

 // Copyright 2013 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.
 
 #include "mojo/system/message_pipe.h"
 
 #include "base/logging.h"
 #include "mojo/system/channel.h"
 #include "mojo/system/local_message_pipe_endpoint.h"
 #include "mojo/system/message_in_transit.h"
@@ skipping 137 matching lines @@
 
 void MessagePipe::ConvertLocalToProxy(unsigned port) {
   DCHECK(port == 0 || port == 1);
 
   base::AutoLock locker(lock_);
   DCHECK(endpoints_[port]);
   DCHECK_EQ(endpoints_[port]->GetType(), MessagePipeEndpoint::kTypeLocal);
 
   bool is_peer_open = !!endpoints_[GetPeerPort(port)];
 
-  // TODO(vtl): Hopefully this will work if the peer has been closed and when
-  // the peer is local. If the peer is remote, we should do something more
-  // sophisticated.
-  DCHECK(!is_peer_open ||
-         endpoints_[GetPeerPort(port)]->GetType() ==
-             MessagePipeEndpoint::kTypeLocal);
+  // TODO(vtl): Allowing this case is a temporary hack. It'll set up a
+  // |MessagePipe| with two proxy endpoints, which will then act as a proxy
+  // (rather than trying to connect the two ends directly).
+  DLOG_IF(WARNING,
+          is_peer_open &&
+              endpoints_[GetPeerPort(port)]->GetType() !=
+                  MessagePipeEndpoint::kTypeLocal)
+      << "Direct message pipe passing across multiple channels not yet "
+         "implemented; will proxy";
 
   scoped_ptr<MessagePipeEndpoint> replacement_endpoint(
       new ProxyMessagePipeEndpoint(
           static_cast<LocalMessagePipeEndpoint*>(endpoints_[port].get()),
           is_peer_open));
   endpoints_[port].swap(replacement_endpoint);
 }
 
 MojoResult MessagePipe::EnqueueMessage(unsigned port,
                                        scoped_ptr<MessageInTransit> message) {
@@ skipping 129 matching lines @@
 MojoResult MessagePipe::HandleControlMessage(
     unsigned /*port*/,
     scoped_ptr<MessageInTransit> message) {
   LOG(WARNING) << "Unrecognized MessagePipe control message subtype "
                << message->subtype();
   return MOJO_RESULT_UNKNOWN;
 }
 
 }  // namespace system
 }  // namespace mojo