Use random debug port in basic_debugger_test.

tests/standalone/debugger/debug_lib.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.
 
 // Library used by debugger wire protocol tests (standalone VM debugging).
 
 library DartDebugger;
 
 import "dart:io";
 import "dart:utf";
 import "dart:json" as JSON;
 
-// TODO(hausner): need to select a different port number for each
-// test that runs in parallel.
-var debugPort = 5860;
-
 // Whether or not to print debug target process on the console.
 var showDebuggeeOutput = true;
 
 // Whether or not to print the debugger wire messages on the console.
 var verboseWire = false;
 
 // Class to buffer wire protocol data from debug target and
 // break it down to individual json messages.
 class JsonBuffer {
   String buffer = null;
@@ skipping 464 matching lines @@
   void close({killDebugee: false}) {
     if (errorsDetected) {
       for (int i = 0; i < errors.length; i++) print(errors[i]);
     }
     socket.close();
     if (killDebugee) {
       targetProcess.kill();
       print("Target process killed");
     }
     Expect.isTrue(!errorsDetected);
-    stdin.close();
-    stdout.close();
-    stderr.close();
+    exit(errors.length);
   }
 }
 
 
-bool RunScript(List script) {
+bool RunScript(List script, int debugPort) {
   var options = new Options();
   if (options.arguments.contains("--debuggee")) {
     return false;
   }
   // The default is to show debugging output.
   showDebuggeeOutput = !options.arguments.contains("--non-verbose");
   verboseWire = options.arguments.contains("--wire");
 
   var targetOpts = [ "--debug:$debugPort" ];
   if (showDebuggeeOutput) targetOpts.add("--verbose_debug");
   targetOpts.add(options.script);
   targetOpts.add("--debuggee");
 
   Process.start(options.executable, targetOpts).then((Process process) {
     print("Debug target process started");
     process.stdin.close();
     process.exitCode.then((int exitCode) {
       Expect.equals(0, exitCode);
       print("Debug target process exited with exit code $exitCode");
     });
     var debugger = new Debugger(process, debugPort);
     debugger.runScript(script);
   });
   return true;
 }