Hide Isolate pointer from embedder

runtime/vm/service_isolate.cc

 // Copyright (c) 2015, 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 "vm/service_isolate.h"
 
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
@@ skipping 579 matching lines @@
 
     Dart_IsolateCreateCallback create_callback =
         ServiceIsolate::create_callback();
     // TODO(johnmccutchan): Support starting up service isolate without embedder
     // provided isolate creation callback.
     if (create_callback == NULL) {
       ServiceIsolate::FinishedInitializing();
       return;
     }
 
-    isolate =
-        reinterpret_cast<Isolate*>(create_callback(ServiceIsolate::kName,
-                                                   NULL,
-                                                   NULL,
-                                                   NULL,
-                                                   &error));
+    isolate = Api::CastIsolate(create_callback(ServiceIsolate::kName,
+                                               NULL,
+                                               NULL,
+                                               NULL,
+                                               &error));
     if (isolate == NULL) {
       OS::PrintErr("vm-service: Isolate creation error: %s\n", error);
       ServiceIsolate::FinishedInitializing();
       return;
     }
 
     Thread::ExitIsolate();
 
     ServiceIsolate::ConstructExitMessageAndCache(isolate);
 
@@ skipping 155 matching lines @@
     return result;
   }
   Dart_Handle source = GetSource(url_string);
   if (Dart_IsError(source)) {
     return source;
   }
   return Dart_LoadSource(library, url, source, 0, 0);
 }
 
 }  // namespace dart