Web MIDI: newly attached device was not registered to listen

media/midi/midi_manager_mac.cc

 // Copyright (c) 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 "media/midi/midi_manager_mac.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 205 matching lines @@
         reinterpret_cast<const MIDIObjectAddRemoveNotification*>(message);
     MIDIEndpointRef endpoint =
         static_cast<MIDIEndpointRef>(notification->child);
     if (notification->childType == kMIDIObjectType_Source) {
       SourceMap::iterator it = source_map_.find(endpoint);
       if (it == source_map_.end()) {
         uint32 index = source_map_.size();
         source_map_[endpoint] = index;
         MidiPortInfo info = GetPortInfoFromEndpoint(endpoint);
         AddInputPort(info);
+        MIDIPortConnectSource(
+            coremidi_input_, endpoint, reinterpret_cast<void*>(endpoint));
       } else {
         uint32 index = it->second;
         SetInputPortState(index, MIDI_PORT_OPENED);
       }
     } else if (notification->childType == kMIDIObjectType_Destination) {
       auto i = std::find(destinations_.begin(), destinations_.end(), endpoint);
       if (i != destinations_.end()) {
         SetOutputPortState(i - destinations_.begin(), MIDI_PORT_OPENED);
       } else {
         destinations_.push_back(endpoint);
@@ skipping 89 matching lines @@
 
   MIDISend(coremidi_output_, destination, packet_list_);
 
   // Re-initialize for next time.
   midi_packet_ = MIDIPacketListInit(packet_list_);
 
   client->AccumulateMidiBytesSent(data.size());
 }
 
 }  // namespace media