[WIP] bindings: Introduce PropertyBag

Source/modules/webmidi/MIDIOptions.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 21 matching lines @@
 #define MIDIOptions_h
 
 #include "bindings/core/v8/Dictionary.h"
 
 namespace blink {
 
 struct MIDIOptions  {
     explicit MIDIOptions(const Dictionary& options)
         : sysex(false)
     {
-        DictionaryHelper::get(options, "sysex", sysex);
+        options.get("sysex", sysex);
     }
 
     bool sysex;
 };
 
 } // namespace blink
 
 #endif // MIDIOptions_h