Web MIDI: make MidiManagerMac notify device connections

media/midi/midi_manager_alsa.cc

Index: media/midi/midi_manager_alsa.cc
diff --git a/media/midi/midi_manager_alsa.cc b/media/midi/midi_manager_alsa.cc
index e4cadfb047b553420907350f6d479f7c8a77d9c1..9043f1f8cc1223eff2cf268053f25240d979ffb6 100644
--- a/media/midi/midi_manager_alsa.cc
+++ b/media/midi/midi_manager_alsa.cc
@@ -252,7 +252,8 @@ void MidiManagerAlsa::StartInitialization() {
             VLOG(1) << "snd_seq_subscribe_port fails: " << snd_strerror(err);
           } else {
             source_map_[AddrToInt(sender)] = current_input++;
-            AddInputPort(MidiPortInfo(id, manufacturer, name, version));
+            AddInputPort(MidiPortInfo(
+                id, manufacturer, name, version, MIDI_PORT_OPENED));
           }
         }
         if ((caps & kRequiredOutputPortCaps) == kRequiredOutputPortCaps) {
@@ -286,7 +287,8 @@ void MidiManagerAlsa::StartInitialization() {
             snd_midi_event_new(kSendBufferSize, &encoder);
             encoders_.push_back(encoder);
             out_ports_.push_back(out_port);
-            AddOutputPort(MidiPortInfo(id, manufacturer, name, version));
+            AddOutputPort(MidiPortInfo(
+                id, manufacturer, name, version, MIDI_PORT_OPENED));
           }
         }
       }