Use ChannelMojo between app shims and the browser process.

mojo/edk/system/node_controller.cc

 // Copyright 2016 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/edk/system/node_controller.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/bind.h"
@@ skipping 1251 matching lines @@
     DLOG(ERROR) << "Received unexpected AcceptPeer message from " << from_node;
     DropPeer(from_node, nullptr);
     return;
   }
 
   scoped_refptr<NodeChannel> channel = it->second.first;
   ports::PortRef local_port = it->second.second;
   pending_peers_.erase(it);
   DCHECK(channel);
 
-  DVLOG(1) << "Node " << name_ << " accepted peer " << peer_name;
+  // If the peer connection is a self connection (which is used in tests),
+  // drop the channel to it and skip straight to merging the ports.
+  if (name_ != peer_name) {
+    DVLOG(1) << "Node " << name_ << " accepted peer " << peer_name;
 
-  AddPeer(peer_name, channel, false /* start_channel */);
+    AddPeer(peer_name, channel, false /* start_channel */);
+  }
 
   // We need to choose one side to initiate the port merge. It doesn't matter
   // who does it as long as they don't both try. Simple solution: pick the one
   // with the "smaller" port name.
   if (local_port.name() < port_name) {
     node()->MergePorts(local_port, peer_name, port_name);
   }
 }
 
 void NodeController::OnChannelError(const ports::NodeName& from_node,
@@ skipping 64 matching lines @@
     shutdown_callback_flag_.Set(false);
   }
 
   DCHECK(!callback.is_null());
 
   callback.Run();
 }
 
 }  // namespace edk
 }  // namespace mojo