Never return a Dart_Handle on a dart::Class from the embedding API.

runtime/include/dart_debugger_api.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef INCLUDE_DART_DEBUGGER_API_H_
 #define INCLUDE_DART_DEBUGGER_API_H_
 
 #include "include/dart_api.h"
 
 typedef struct _Dart_Breakpoint* Dart_Breakpoint;
@@ skipping 499 matching lines @@
  *
  * Requires there to be a current isolate.
  *
  * \return True if no error occurs.
  */
 DART_EXPORT Dart_Handle Dart_GetObjClassId(Dart_Handle object,
                                            intptr_t* class_id);
 
 
 /**
- * Returns the superclass of the given class \cls.
- *
- * Requires there to be a current isolate.
- *
- * \return A handle to the class object.
- */
-DART_EXPORT Dart_Handle Dart_GetSuperclass(Dart_Handle cls);
-
-
-/**
  * Returns the supertype of the given instantiated type \cls.
  *
  * Requires there to be a current isolate.
  *
  * \return A handle to the type object.
  */
 DART_EXPORT Dart_Handle Dart_GetSupertype(Dart_Handle type);
 
 
 /**
@@ skipping 136 matching lines @@
  * \param request A REST-like string, which uses '/' to separate
  *     parameters. The first parameter is always the status type.
  *
  * \return The requested status as a JSON formatted string, with the
  *     contents defined by the status plug-in. The caller is responsible
  *     for freeing this string.
  */
 DART_EXPORT char* Dart_GetVmStatus(const char* request);
 
 #endif  // INCLUDE_DART_DEBUGGER_API_H_