Web MIDI: implement MIDIInput

Source/core/dom/EventTarget.h

Index: Source/core/dom/EventTarget.h
diff --git a/Source/core/dom/EventTarget.h b/Source/core/dom/EventTarget.h
index 73646ceceab56071d6c7153359a5c05a2584da3b..7bf80c9493ff1cca6540eb63838eb9054f49eaa3 100644
--- a/Source/core/dom/EventTarget.h
+++ b/Source/core/dom/EventTarget.h
@@ -52,7 +52,7 @@ namespace WebCore {
     class IDBDatabase;
     class IDBRequest;
     class IDBTransaction;
-    class ScriptProcessorNode;
+    class MIDIInput;
     class MIDIPort;
     class MediaController;
     class MediaSource;
@@ -63,6 +63,7 @@ namespace WebCore {
     class Notification;
     class SVGElementInstance;
     class ScriptExecutionContext;
+    class ScriptProcessorNode;
     class SharedWorker;
     class SharedWorkerContext;
     class SourceBufferList;