Web MIDI: add blink APIs to notify device connection events

Source/modules/webmidi/MIDIPort.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 39 matching lines @@
 
     virtual ~MIDIPort() { }
 
     String id() const { return m_id; }
     String manufacturer() const { return m_manufacturer; }
     String name() const { return m_name; }
     String type() const;
     String version() const { return m_version; }
 
     MIDIAccess* midiAccess() const { return m_access; }
+    bool isActive() const { return m_isActive; }
+    void setActiveState(bool isActive) { m_isActive = isActive; }
 
     virtual void trace(Visitor*) override;
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(disconnect);
 
     // EventTarget
     virtual const AtomicString& interfaceName() const override { return EventTargetNames::MIDIPort; }
     virtual ExecutionContext* executionContext() const override final;
 
 protected:
-    MIDIPort(MIDIAccess*, const String& id, const String& manufacturer, const String& name, MIDIPortTypeCode, const String& version);
+    MIDIPort(MIDIAccess*, const String& id, const String& manufacturer, const String& name, MIDIPortTypeCode, const String& version, bool isActive);
 
 private:
     String m_id;
     String m_manufacturer;
     String m_name;
     MIDIPortTypeCode m_type;
     String m_version;
     Member<MIDIAccess> m_access;
+    bool m_isActive;
 };
 
 } // namespace blink
 
 #endif // MIDIPort_h