Web MIDI: implement receiving for dynamic manager instantiation on Windows

media/midi/dynamically_initialized_midi_manager_win.h

Index: media/midi/dynamically_initialized_midi_manager_win.h
diff --git a/media/midi/dynamically_initialized_midi_manager_win.h b/media/midi/dynamically_initialized_midi_manager_win.h
index 8c36f76511cfc4a149f305cef7e07d824bc2ec43..b72d6c0de9b8b5b466d5cf8abe8a28a8c249cbaa 100644
--- a/media/midi/dynamically_initialized_midi_manager_win.h
+++ b/media/midi/dynamically_initialized_midi_manager_win.h
@@ -28,6 +28,14 @@ class DynamicallyInitializedMidiManagerWin final
   explicit DynamicallyInitializedMidiManagerWin(MidiService* service);
   ~DynamicallyInitializedMidiManagerWin() override;
 
+  // Calculates event time from elapsed time that system provides.
+  base::TimeTicks CalculateInEventTime(size_t index, uint32_t elapsed_ms) const;
+
+  // Handles MIDI inport event posted from a thread system provides.
+  void ReceiveMidiData(uint32_t index,
+                       const std::vector<uint8_t>& data,
+                       base::TimeTicks time);
+
   // Posts a reply task to the I/O thread that hosts MidiManager instance, runs
   // it safely, and ensures that the instance keeps alive while the task is
   // running.