Web MIDI: implement MIDIMessageEvent

Source/modules/webmidi/MIDIMessageEvent.idl

Index: Source/modules/webmidi/MIDIMessageEvent.idl
diff --git a/Source/core/css/CSSFontFaceLoadEvent.idl b/Source/modules/webmidi/MIDIMessageEvent.idl
similarity index 83%
copy from Source/core/css/CSSFontFaceLoadEvent.idl
copy to Source/modules/webmidi/MIDIMessageEvent.idl
index c4bd55e2f9d474a063aa8c356bc129e8be6366a5..937301137b0df111d5d030b31572b287c59af602 100644
--- a/Source/core/css/CSSFontFaceLoadEvent.idl
+++ b/Source/modules/webmidi/MIDIMessageEvent.idl
@@ -28,10 +28,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+// FIXME: The spec doesn't provide details about constructor, yet.
+// See also, https://github.com/WebAudio/web-midi-api/issues/1 .
 [
-    EnabledAtRuntime=fontLoadEvents,
     ConstructorTemplate=Event
-] interface CSSFontFaceLoadEvent : Event {
-    [InitializedByEventConstructor] readonly attribute CSSFontFaceRule fontface;
-    [InitializedByEventConstructor] readonly attribute DOMError error;
+] interface MIDIMessageEvent : Event {
+    [InitializedByEventConstructor] readonly attribute double receivedTime;
+    [InitializedByEventConstructor] readonly attribute Uint8Array data;
 };