Revert "Per isolate package root."

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 702 matching lines @@
  *   Dart_LoadScript or Dart_LoadScriptFromSnapshot.
  *   This uri will be NULL if the isolate is being created using the
  *   spawnFunction isolate API.
  *   The callback is responsible for loading the script used in the
  *   parent isolate by a call to Dart_LoadScript or
  *   Dart_LoadScriptFromSnapshot.
  * \param main The name of the main entry point this isolate will
  *   eventually run.  This is provided for advisory purposes only to
  *   improve debugging messages.  The main function is not invoked by
  *   this function.
- * \param package_root The package root path for this isolate to resolve
- *   package imports against. If this parameter is NULL, the package root path
- *   of the parent isolate should be used.
  * \param callback_data The callback data which was passed to the
  *   parent isolate when it was created by calling Dart_CreateIsolate().
  * \param error A structure into which the embedder can place a
  *   C string containing an error message in the case of failures.
  *
  * \return The embedder returns NULL if the creation and
  *   initialization was not successful and the isolate if successful.
  */
 typedef Dart_Isolate (*Dart_IsolateCreateCallback)(const char* script_uri,
                                                    const char* main,
-                                                   const char* package_root,
                                                    void* callback_data,
                                                    char** error);
 
 
 /**
  * The service isolate creation and initialization callback function.
  *
  * This callback, provided by the embedder, is called when the vm
  * needs to create the service isolate. The callback should create an isolate
  * by calling Dart_CreateIsolate and prepare the isolate to be used as
@@ skipping 2090 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 */