Fixing custom element type extensions to have correct native type

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 377 matching lines @@
         return false;
     }
 
     Dart_Handle exception = 0;
     bool boolResult = dartToBool(result, exception);
     if (exception)
         return false;
     return boolResult;
 }
 
-bool DartUtilities::isTypeSubclassOfTag(Dart_Handle type, const String& tagName)
+Dart_Handle DartUtilities::getAndValidateNativeType(Dart_Handle type, const String& tagName)
 {
     Dart_Handle args[2] = { type, stringToDartString(tagName) };
-    Dart_Handle result = DartUtilities::invokeUtilsMethod("isTypeSubclassOfTag", 2, args);
+    Dart_Handle result = DartUtilities::invokeUtilsMethod("getAndValidateNativeType", 2, args);
     ASSERT(!Dart_IsError(result));
     if (Dart_IsError(result)) {
         ASSERT_NOT_REACHED();
-        return false;
+        return Dart_Null();
     }
-
-    Dart_Handle exception = 0;
-    bool boolResult = dartToBool(result, exception);
-    if (exception)
-        return false;
-    return boolResult;
+    return result;
 }
 
 bool DartUtilities::isTypedData(Dart_Handle handle)
 {
     return (Dart_GetTypeOfTypedData(handle) != Dart_TypedData_kInvalid)
         || (Dart_GetTypeOfExternalTypedData(handle) != Dart_TypedData_kInvalid);
 }
 
 static Dart_TypedData_Type typedDataTypeFromViewType(ArrayBufferView::ViewType type)
 {
@@ skipping 667 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);
 }
 
 }