Fix line width issue.

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 290 matching lines @@
  *
  * \param error the error message.
  */
 DART_EXPORT Dart_Handle Dart_NewApiError(const char* error);
 
 /**
  * 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.
+ * \param exception An instance of a Dart object to be thrown or
+ *        an ApiError or CompilationError handle.
+ *        When an ApiError or CompilationError handle is passed in
+ *        a string object of the error message is created and it becomes
+ *        the Dart object to be thrown.
  */
 DART_EXPORT Dart_Handle Dart_NewUnhandledExceptionError(Dart_Handle exception);
 
 /**
  * Propagates an error.
  *
  * If the provided handle is an unhandled exception error, this
  * function will cause the unhandled exception to be rethrown.  This
  * will proceed in the standard way, walking up Dart frames until an
  * appropriate 'catch' block is found, executing 'finally' blocks,
@@ skipping 2507 matching lines @@
 
 /**
  * Returns the port that script load requests should be sent on.
  *
  * \return Returns the port for load requests or ILLEGAL_PORT if the service
  * isolate failed to startup or does not support load requests.
  */
 DART_EXPORT Dart_Port Dart_ServiceWaitForLoadPort();
 
 #endif  /* INCLUDE_DART_API_H_ */  /* NOLINT */