Web MIDI: add dynamic MidiManager instantiation support for Linux

media/midi/midi_manager_mac.h

 // 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.
 
 #ifndef MEDIA_MIDI_MIDI_MANAGER_MAC_H_
 #define MEDIA_MIDI_MIDI_MANAGER_MAC_H_
 
 #include <CoreMIDI/MIDIServices.h>
 #include <stdint.h>
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/threading/thread.h"
 #include "media/midi/midi_export.h"
 #include "media/midi/midi_manager.h"
 #include "media/midi/midi_port_info.h"
 
 namespace midi {
 
+class MidiService;
+
 class MIDI_EXPORT MidiManagerMac final : public MidiManager {
  public:
-  MidiManagerMac();
+  MidiManagerMac(MidiService* service);

[yhirano, 2017/02/08 10:04:37]

+explicit

[Takashi Toyoshima, 2017/02/08 11:08:55]

Done.

   ~MidiManagerMac() override;
 
   // MidiManager implementation.
   void StartInitialization() override;
   void Finalize() override;
   void DispatchSendMidiData(MidiManagerClient* client,
                             uint32_t port_index,
                             const std::vector<uint8_t>& data,
                             double timestamp) override;
 
@@ skipping 47 matching lines @@
 
   // Sets true on destructing object to avoid starting |client_thread_| again.
   bool shutdown_;
 
   DISALLOW_COPY_AND_ASSIGN(MidiManagerMac);
 };
 
 }  // namespace midi
 
 #endif  // MEDIA_MIDI_MIDI_MANAGER_MAC_H_