Some more removals of dart:utf.

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
 //
 //   --wire      see json messages sent between the processes.
 //   --verbose   see the stdout and stderr output of the debug
 //               target process.
 
 import "dart:convert";
 import "dart:io";
-import "dart:utf";
 import "dart:json" as JSON;
 
 
 // Whether or not to print debug target process on the console.
 var showDebuggeeOutput = false;
 
 // Whether or not to print the debugger wire messages on the console.
 var verboseWire = false;
 
 var debugger = null;
@@ skipping 511 matching lines @@
         targetOpts.add(str);
         break;
     }
   }
 
   Process.start(options.executable, targetOpts).then((Process process) {
     process.stdin.close();
     debugger = new Debugger(process);
   });
 }