Cleanup isolate library after frog removal.

lib/isolate/dart2js/isolateimpl.dart

 // 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.
 
 /**
  * Concepts used here:
  *
  * "manager" - A manager contains one or more isolates, schedules their
  * execution, and performs other plumbing on their behalf.  The isolate
  * present at the creation of the manager is designated as its "root isolate".
@@ skipping 626 matching lines @@
       'command': 'start2',
       'id': workerId,
       // Note: we serialize replyPort twice because the child worker needs to
       // first deserialize the worker id, before it can correctly deserialize
       // the port (port deserialization is sensitive to what is the current
       // workerId).
       'replyTo': _serializeMessage(replyPort),
       'functionName': functionName }));
   }
 }