Use Dart_InstanceIsSubtypeOf to check if instance is a direct subtype of specified 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 324 matching lines @@
 
 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);
+    return DartDOMWrapper::subtypeOf<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);

[rmacnak, 2013/10/14 17:37:26]

Should we be using the new test here too?

 }
 
 bool DartUtilities::isBlob(DartDOMData* domData, Dart_Handle handle)
 {
     ASSERT(domData);
-    return DartDOMWrapper::instanceOf<DartBlob>(domData, handle);
+    return DartDOMWrapper::subtypeOf<DartBlob>(domData, handle);
 }
 
 bool DartUtilities::isImageData(DartDOMData* domData, Dart_Handle handle)
 {
     ASSERT(domData);
-    return DartDOMWrapper::instanceOf<DartImageData>(domData, handle);
+    return DartDOMWrapper::subtypeOf<DartImageData>(domData, handle);
 }
 
 bool DartUtilities::isIDBKeyRange(DartDOMData* domData, Dart_Handle handle)
 {
     ASSERT(domData);
-    return DartDOMWrapper::instanceOf<DartIDBKeyRange>(domData, handle);
+    return DartDOMWrapper::subtypeOf<DartIDBKeyRange>(domData, handle);
 }
 
 bool DartUtilities::objectIsType(Dart_Handle handle, Dart_Handle type)
 {
     bool isType = false;
     Dart_Handle result = Dart_ObjectIsType(handle, type, &isType);
     if (Dart_IsError(result))
         return false;
     return isType;
 }
@@ skipping 413 matching lines @@
 void DartUtilities::toMessagePortArray(Dart_Handle value, MessagePortArray& ports, ArrayBufferArray& arrayBuffers, Dart_Handle& exception)
 {
     Vector<Dart_Handle> elements;
     DartUtilities::extractListElements(value, exception, elements);
     if (exception)
         return;
 
     DartDOMData* domData = DartDOMData::current();
     for (size_t i = 0; i < elements.size(); i++) {
         Dart_Handle element = elements[i];
-        if (DartDOMWrapper::instanceOf<DartMessagePort>(domData, element)) {
+        if (DartDOMWrapper::subtypeOf<DartMessagePort>(domData, element)) {
             MessagePort* messagePort = DartMessagePort::toNative(element, exception);
             ASSERT(!exception);
             ASSERT(messagePort);
             ports.append(messagePort);
             continue;
         }
 
         // FIXME: We need better type testing functionality. Currently this is not
         // disallowing views and it should.
         if (DartUtilities::isTypedData(element)) {
@@ skipping 264 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);
 }
 
 }