Add a native subtype of function that uses the native C++ class hierarchy to check if an element

Source/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 321 matching lines @@
 
     return DartUtilities::dartToDouble(asDouble, exception);
 }
 
 double DartUtilities::dartToDate(Dart_NativeArguments args, int idx, Dart_Handle& exception)
 {
     Dart_Handle object = Dart_GetNativeArgument(args, idx);
     return dartToDate(object, exception);
 }
 
-bool DartUtilities::isHtmlElement(DartDOMData* domData, Dart_Handle handle)
-{
-    ASSERT(domData);
-    return DartDOMWrapper::instanceOf<DartHTMLElement>(domData, handle);
-}
-
 bool DartUtilities::isDateTime(DartDOMData* domData, Dart_Handle handle)
 {
     ASSERT(domData);
     Dart_Handle type = DartDOMWrapper::dartClass(
         domData, "DateTime", DartCoreLibraryId, _DateTimeClassId);
     ASSERT(!Dart_IsError(type));
     return objectIsType(handle, type);
 }
 
 bool DartUtilities::isBlob(DartDOMData* domData, Dart_Handle handle)
@@ skipping 741 matching lines @@
     Dart_PersistentHandle library = domData->htmlLibrary();
     ASSERT(!Dart_IsError(library));
 
     Dart_Handle utilsClass = Dart_GetType(library, Dart_NewStringFromCString("_Utils"), 0, 0);
     ASSERT(!Dart_IsError(utilsClass));
 
     return Dart_Invoke(utilsClass, Dart_NewStringFromCString(methodName), argCount, args);
 }
 
 }