Revert "Hide Isolate pointer from embedder"

samples/sample_extension/sample_extension.cc

 // 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.
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 
 
@@ skipping 63 matching lines @@
   srand(seed);
   for (int i = 0; i < length; ++i) {
     values[i] = rand() % 256;
   }
   return values;
 }
 
 
 void wrappedRandomArray(Dart_Port dest_port_id,
                         Dart_CObject* message) {
-  Dart_Port reply_port_id = DART_ILLEGAL_PORT;
+  Dart_Port reply_port_id = ILLEGAL_PORT;
   if (message->type == Dart_CObject_kArray &&
       3 == message->value.as_array.length) {
     // Use .as_array and .as_int32 to access the data in the Dart_CObject.
     Dart_CObject* param0 = message->value.as_array.values[0];
     Dart_CObject* param1 = message->value.as_array.values[1];
     Dart_CObject* param2 = message->value.as_array.values[2];
     if (param0->type == Dart_CObject_kInt32 &&
         param1->type == Dart_CObject_kInt32 &&
         param2->type == Dart_CObject_kSendPort) {
       int seed = param0->value.as_int32;
@@ skipping 19 matching lines @@
   result.type = Dart_CObject_kNull;
   Dart_PostCObject(reply_port_id, &result);
 }
 
 
 void randomArrayServicePort(Dart_NativeArguments arguments) {
   Dart_EnterScope();
   Dart_SetReturnValue(arguments, Dart_Null());
   Dart_Port service_port =
       Dart_NewNativePort("RandomArrayService", wrappedRandomArray, true);
-  if (service_port != DART_ILLEGAL_PORT) {
+  if (service_port != ILLEGAL_PORT) {
     Dart_Handle send_port = HandleError(Dart_NewSendPort(service_port));
     Dart_SetReturnValue(arguments, send_port);
   }
   Dart_ExitScope();
 }
 
 
 struct FunctionLookup {
   const char* name;
   Dart_NativeFunction function;
@@ skipping 44 matching lines @@
     if (strcmp(no_scope_function_list[i].name, cname) == 0) {
       *auto_setup_scope = false;
       result = no_scope_function_list[i].function;
       break;
     }
   }
 
   Dart_ExitScope();
   return result;
 }