Web MIDI: add blink APIs to notify device connection events

Source/modules/webmidi/MIDIAccessInitializer.h

Index: Source/modules/webmidi/MIDIAccessInitializer.h
diff --git a/Source/modules/webmidi/MIDIAccessInitializer.h b/Source/modules/webmidi/MIDIAccessInitializer.h
index 691224f619f89f1e8ee02e3de4d6d12c7713b7fb..71375e5635e40565a3b852a125914a95074e8e17 100644
--- a/Source/modules/webmidi/MIDIAccessInitializer.h
+++ b/Source/modules/webmidi/MIDIAccessInitializer.h
@@ -28,13 +28,15 @@ public:
         String name;
         MIDIPort::MIDIPortTypeCode type;
         String version;
+        bool active;
 
-        PortDescriptor(const String& id, const String& manufacturer, const String& name, MIDIPort::MIDIPortTypeCode type, const String& version)
+        PortDescriptor(const String& id, const String& manufacturer, const String& name, MIDIPort::MIDIPortTypeCode type, const String& version, bool active)
             : id(id)
             , manufacturer(manufacturer)
             , name(name)
             , type(type)
-            , version(version) { }
+            , version(version)
+            , active(active) { }
     };
 
     static ScriptPromise start(ScriptState* scriptState, const MIDIOptions& options)
@@ -48,8 +50,10 @@ public:
     virtual ~MIDIAccessInitializer();
 
     // MIDIAccessorClient
-    virtual void didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version) override;
-    virtual void didAddOutputPort(const String& id, const String& manufacturer, const String& name, const String& version) override;
+    virtual void didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version, bool active) override;
+    virtual void didAddOutputPort(const String& id, const String& manufacturer, const String& name, const String& version, bool active) override;
+    virtual void didSetInputPortState(unsigned portIndex, bool active) override;
+    virtual void didSetOutputPortState(unsigned portIndex, bool active) override;
     virtual void didStartSession(bool success, const String& error, const String& message) override;
     virtual void didReceiveMIDIData(unsigned portIndex, const unsigned char* data, size_t length, double timeStamp) override { }