[WIP] bindings: Introduce PropertyBag

Source/core/frame/LocalDOMWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 1335 matching lines @@
 {
     if (!m_frame)
         return 0.0;
 
     return m_frame->devicePixelRatio();
 }
 
 static bool scrollBehaviorFromScrollOptions(const Dictionary& scrollOptions, ScrollBehavior& scrollBehavior, ExceptionState& exceptionState)
 {
     String scrollBehaviorString;
-    if (!DictionaryHelper::get(scrollOptions, "behavior", scrollBehaviorString)) {
+    if (!scrollOptions.get("behavior", scrollBehaviorString)) {
         scrollBehavior = ScrollBehaviorAuto;
         return true;
     }
 
     if (ScrollableArea::scrollBehaviorFromString(scrollBehaviorString, scrollBehavior))
         return true;
 
     exceptionState.throwTypeError("The ScrollBehavior provided is invalid.");
     return false;
 }
@@ skipping 548 matching lines @@
     visitor->trace(m_applicationCache);
     visitor->trace(m_performance);
     visitor->trace(m_css);
     visitor->trace(m_eventQueue);
     WillBeHeapSupplementable<LocalDOMWindow>::trace(visitor);
     EventTargetWithInlineData::trace(visitor);
     LifecycleContext<LocalDOMWindow>::trace(visitor);
 }
 
 } // namespace blink