Added the ability for testrunner to start the HTTP server with a random port and communicate that p…

utils/testrunner/pipeline_utils.dart

Index: utils/testrunner/pipeline_utils.dart
===================================================================
--- utils/testrunner/pipeline_utils.dart	(revision 13499)
+++ utils/testrunner/pipeline_utils.dart	(working copy)
@@ -58,14 +58,12 @@
  */
 Future _processHelper(String command, List<String> args,
     [int timeout = 300, int procId = 0]) {
-  var completer = null;
+  var completer = new Completer();
   log.add('Running $command ${Strings.join(args, " ")}');
   var timer = null;
   var stdoutHandler, stderrHandler;
   var process = Process.start(command, args);
-  if (procId == 0) {
-    completer = new Completer();
-  } else {
+  if (procId != 0) {
     _procs[procId] = process;
   }
   process.onStart = () {
@@ -93,7 +91,7 @@
   _pipeStream(process.stdout, stdout);
   _pipeStream(process.stderr, stderr);
 
-  return (completer == null) ? null : completer.future;
+  return completer.future;
 }
 
 void _pipeStream(InputStream stream, List<String> destination) {
@@ -128,17 +126,26 @@
  */
 int startProcess(String command, List<String> args) {
   int id = _procId++;
-  _processHelper(command, args, 3000, id);
+  _processHelper(command, args, 3000, id).then((e) {
+    _procs.remove(id);
+  });
   return id;
 }
 
+/** Checks if a process is still running. */
+bool isProcessRunning(int id) {
+  return _procs.containsKey(id);
+}
+
 /**
  * Stop a process previously started with [startProcess] or [runCommand],
  * given the id string.
  */
 void stopProcess(int id) {
-  Process p = _procs.remove(id);
-  p.kill();
+  if (_procs.containsKey(id)) {
+    Process p = _procs.remove(id);
+    p.kill();
+  }
 }
 
 /** Delete a file named [fname] if it exists. */