[WebMIDI] Add "use-android-midi-api" flag for Android M+ devices.

media/midi/midi_manager.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_H_
 #define MEDIA_MIDI_MIDI_MANAGER_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 50 matching lines @@
   // This happens as a result of the client having previously called
   // MidiManager::DispatchSendMidiData().
   virtual void AccumulateMidiBytesSent(size_t n) = 0;
 };
 
 // Manages access to all MIDI hardware.
 class MIDI_EXPORT MidiManager {
  public:
   static const size_t kMaxPendingClientCount = 128;
 
+  class CreationOptions {
+   public:
+#if defined(OS_ANDROID)
+    bool use_native_midi_api() const { return use_native_midi_api_; }
+    void set_use_native_midi_api(bool b) { use_native_midi_api_ = b; }
+#endif // defined(OS_ANDROID)
+
+   private:
+#if defined(OS_ANDROID)
+    bool use_native_midi_api_ = false;
+#endif // defined(OS_ANDROID)
+  };
+
   MidiManager();
   virtual ~MidiManager();
 
   // The constructor and the destructor will be called on the CrBrowserMain
   // thread.
-  static MidiManager* Create();
+  static MidiManager* Create(const CreationOptions&);
 
   // A client calls StartSession() to receive and send MIDI data.
   // If the session is ready to start, the MIDI system is lazily initialized
   // and the client is registered to receive MIDI data.
   // CompleteStartSession() is called with Result::OK if the session is started.
   // Otherwise CompleteStartSession() is called with proper Result code.
   // StartSession() and EndSession() can be called on the Chrome_IOThread.
   // CompleteStartSession() will be invoked on the same Chrome_IOThread.
   void StartSession(MidiManagerClient* client);
 
@@ skipping 94 matching lines @@
   // |result_|, |input_ports_| and |output_ports_|.
   base::Lock lock_;
 
   DISALLOW_COPY_AND_ASSIGN(MidiManager);
 };
 
 }  // namespace midi
 }  // namespace media
 
 #endif  // MEDIA_MIDI_MIDI_MANAGER_H_