DOM wrappers that are not retained from Dart should be collected.

Source/WebCore/bindings/dart/DartUtilities.cpp

 // Copyright 2011, 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 251 matching lines @@
         , m_recursion(0)
     {
         if (!context)
             return;
 
         ASSERT(context->isDocument()); // WorkerContext is not supported yet.
         Document* document = static_cast<Document*>(context);
         m_domWindow = document->domWindow();
     }
 
+    ~DartDOMData()
+    {
+        ASSERT(m_domMap.isEmpty());
+    }
+
     PassRefPtr<DartApplicationLoader> applicationLoader() { return m_applicationLoader; }
     ScriptExecutionContext* scriptExecutionContext() { return m_scriptExecutionContext; }
     DOMWindow* domWindow() { return m_domWindow; }
     DartDOMMap* domMap() { return &m_domMap; }
     int* recursion() { return &m_recursion; }
 
 private:
     RefPtr<DartApplicationLoader> m_applicationLoader;
     ScriptExecutionContext* m_scriptExecutionContext;
     DOMWindow* m_domWindow;
@@ skipping 11 matching lines @@
 
 static DartDOMData* domDataForIsolate(Dart_Isolate isolate)
 {
     IsolateToDartDOMDataMap::iterator it = isolateToDartDOMDataMap().find(isolate);
     ASSERT(it != isolateToDartDOMDataMap().end());
     return it->second;
 }
 
 static DartDOMData* currentDOMData()
 {
-    return domDataForIsolate(DartIsolate::current()->isolate());
+    return domDataForIsolate(Dart_CurrentIsolate());
 }
 
 void DartUtilities::registerDOMIsolate(Dart_Isolate isolate, PassRefPtr<DartApplicationLoader> applicationLoader, ScriptExecutionContext* context)
 {
     ASSERT(!isolateToDartDOMDataMap().contains(isolate));
     isolateToDartDOMDataMap().set(isolate, new DartDOMData(applicationLoader, context));
     ASSERT(context->isDocument());
 }
 
 void DartUtilities::registerPureIsolate(Dart_Isolate isolate, PassRefPtr<DartApplicationLoader> applicationLoader)
@@ skipping 162 matching lines @@
     ASSERT(!Dart_IsError(library));
     Dart_Handle args[2] = {0};
     args[0] = Dart_NewString(fileName);
     args[1] = Dart_NewInteger(lineNumber);
     Dart_Handle result = Dart_InvokeStatic(library, Dart_NewString("Utils"), Dart_NewString("makeNotImplementedException"), 2, args);
     ASSERT(!Dart_IsError(result));
     return result;
 }
 
 }