Add Dart_IsFuture. To be used in Dartium implementation of Promises.

runtime/include/dart_api.h

 /*
  * Copyright (c) 2012, 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_API_H_
 #define INCLUDE_DART_API_H_
 
 /** \mainpage Dart Embedding API Reference
@@ skipping 1307 matching lines @@
 DART_EXPORT bool Dart_IsList(Dart_Handle object);
 DART_EXPORT bool Dart_IsMap(Dart_Handle object);
 DART_EXPORT bool Dart_IsLibrary(Dart_Handle object);
 DART_EXPORT bool Dart_IsType(Dart_Handle handle);
 DART_EXPORT bool Dart_IsFunction(Dart_Handle handle);
 DART_EXPORT bool Dart_IsVariable(Dart_Handle handle);
 DART_EXPORT bool Dart_IsTypeVariable(Dart_Handle handle);
 DART_EXPORT bool Dart_IsClosure(Dart_Handle object);
 DART_EXPORT bool Dart_IsTypedData(Dart_Handle object);
 DART_EXPORT bool Dart_IsByteBuffer(Dart_Handle object);
+DART_EXPORT bool Dart_IsFuture(Dart_Handle object);
 
 
 /*
  * =========
  * Instances
  * =========
  */
 
 /*
  * For the purposes of the embedding api, not all objects returned are
@@ skipping 1495 matching lines @@
  * NOTE: If multiple callbacks with the same name are registered, only the
  * last callback registered will be remembered.
  */
 DART_EXPORT void Dart_RegisterRootServiceRequestCallback(
     const char* name,
     Dart_ServiceRequestCallback callback,
     void* user_data);
 
 
 #endif  /* INCLUDE_DART_API_H_ */  /* NOLINT */