Fix ambigous typos.

tools/ddbg.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.
 
 // Simple interactive debugger shell that connects to the Dart VM's debugger
 // connection port.
 
 import "dart:convert";
 import "dart:io";
 import "dart:async";
@@ skipping 756 matching lines @@
     var matches = matchCommand(command, true);
     if (matches.length == 0) {
       huh();
       cmdo.show();
     } else if (matches.length == 1) {
       matches[0].run(args).then((_) {
           cmdo.show();
         });
     } else {
       var matchNames = matches.map((handler) => handler.name);
-      print("Ambigous command '$command' : ${matchNames.toList()}");
+      print("Ambiguous command '$command' : ${matchNames.toList()}");
       cmdo.show();
     }
   }
 }
 
 
 void processError(error, trace) {
   cmdo.hide();
   print("\nInternal error:\n$error\n$trace");
   cmdo.show();
@@ skipping 699 matching lines @@
       handleUncaughtError: debuggerError));
 
   zone.run(() {
       parseArgs(args);
       cmdo = new Commando(completer: debuggerCommandCompleter);
       cmdSubscription = cmdo.commands.listen(processCommand,
                                              onError: processError,
                                              onDone: processDone);
     });
 }