Web MIDI: add blink APIs to notify device connection events

Source/modules/webmidi/MIDIAccessorClient.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 19 matching lines @@
 
 #ifndef MIDIAccessorClient_h
 #define MIDIAccessorClient_h
 
 #include "wtf/Forward.h"
 
 namespace blink {
 
 class MIDIAccessorClient {
 public:
-    virtual void didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version) = 0;
-    virtual void didAddOutputPort(const String& id, const String& manufacturer, const String& name, const String& version) = 0;
+    virtual void didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version, bool active) = 0;
+    virtual void didAddOutputPort(const String& id, const String& manufacturer, const String& name, const String& version, bool active) = 0;
+    virtual void didSetInputPortState(unsigned portIndex, bool active) = 0;
+    virtual void didSetOutputPortState(unsigned portIndex, bool active) = 0;
 
     virtual void didStartSession(bool success, const String& error, const String& message) = 0;
     virtual void didReceiveMIDIData(unsigned portIndex, const unsigned char* data, size_t length, double timeStamp) = 0;
 };
 
 } // namespace blink
 
 #endif // MIDIAccessorClient_h