Introduce MIDIInputMap and MIDIOutputMap.

Source/modules/webmidi/MIDIInputMap.h

Index: Source/modules/webmidi/MIDIInputMap.h
diff --git a/Source/modules/webmidi/MIDIInputMap.h b/Source/modules/webmidi/MIDIInputMap.h
new file mode 100644
index 0000000000000000000000000000000000000000..bea5d012ac79d9e1c9086ffef51ac115038b45cf
--- /dev/null
+++ b/Source/modules/webmidi/MIDIInputMap.h
@@ -0,0 +1,31 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MIDIInputMap_h
+#define MIDIInputMap_h
+
+#include "bindings/core/v8/ScriptWrappable.h"
+#include "bindings/core/v8/V8Binding.h"
+#include "modules/webmidi/MIDIInput.h"
+#include "modules/webmidi/MIDIPortMap.h"
+
+namespace blink {
+
+class MIDIInputMap : public MIDIPortMap<MIDIInput>, public ScriptWrappable {
+public:
+    MIDIInputMap(const HeapHashMap<String, Member<MIDIInput> >map)
+        : MIDIPortMap<MIDIInput>(map) { ScriptWrappable::init(this); }
+
+    ScriptValue getPublic(ScriptState* scriptState, const String& id)
+    {
+        MIDIInput* result = get(id);
+        if (result)
+            return ScriptValue(scriptState, V8ValueTraits<MIDIInput*>::toV8Value(result, scriptState->context()->Global(), scriptState->isolate()));
+        return ScriptValue(scriptState, v8::Undefined(scriptState->isolate()));
+    }
+};
+
+} // namespace blink
+
+#endif