Remove deprecated parts of dart:async.

tools/coverage.dart

 // Copyright (c) 2013, 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.
 
 // This test forks a second vm process that runs a dart script as
 // a debug target, single stepping through the entire program, and
 // recording each breakpoint. At the end, a coverage map of the source
 // is printed.
 //
 // Usage: dart coverage.dart [--wire] [--verbose] target_script.dart
@@ skipping 372 matching lines @@
           },
           onDone: () {
             print("Connection closed by coverage target");
             cleanup();
           },
           onError: (e) {
             print("Error '$e' detected in input stream from coverage target");
             cleanup();
           });
       },
-      onError: (e) {
+      onError: (e, trace) {
         String msg = "Error while connecting to coverage target: $e";
-        var trace = getAttachedStackTrace(e);
         if (trace != null) msg += "\nStackTrace: $trace";
         error(msg);
         cleanup();
      });
   }
 
   void cleanup() {
     if (cleanupDone) return;
     if (socket != null) {
       socket.close().catchError((error) {
@@ skipping 132 matching lines @@
         targetOpts.add(str);
         break;
     }
   }
 
   Process.start(options.executable, targetOpts).then((Process process) {
     process.stdin.close();
     debugger = new Debugger(process);
   });
 }