Remove deprecated call Dart_Error from the API. There are no uses of it.

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 279 matching lines @@
 
 /**
  * Produces a new unhandled exception error handle.
  *
  * Requires there to be a current isolate.
  *
  * \param exception An instance of a Dart object to be thrown.
  */
 DART_EXPORT Dart_Handle Dart_NewUnhandledExceptionError(Dart_Handle exception);
 
-/* Deprecated. */
-/* TODO(turnidge): Remove all uses and delete. */
-DART_EXPORT Dart_Handle Dart_Error(const char* error);
-
 /**
  * Propagates an error.
  *
  * If the provided handle is an unhandled exception error, this
  * function will cause the unhandled exception to be rethrown.  This
  * will proceeed in the standard way, walking up Dart frames until an
  * appropriate 'catch' block is found, executing 'finally' blocks,
  * etc.
  *
  * If the error is not an unhandled exception error, we will unwind
@@ skipping 1997 matching lines @@
  *
  * \param object An object.
  * \param peer A value to store in the peer field.
  *
  * \return Returns an error if 'object' is a subtype of Null, num, or
  *   bool.
  */
 DART_EXPORT Dart_Handle Dart_SetPeer(Dart_Handle object, void* peer);
 
 #endif  /* INCLUDE_DART_API_H_ */  /* NOLINT */