Make multi tests work with DartC.

tools/test.dart

Index: tools/test.dart
diff --git a/tools/test.dart b/tools/test.dart
index b61d1abf83436458170671f5a9373c0eff231f96..9ee33f0d139cd20124608e65c3369e0524d79b78 100755
--- a/tools/test.dart
+++ b/tools/test.dart
@@ -23,15 +23,22 @@
 main() {
   var startTime = new Date.now();
   var optionsParser = new TestOptionsParser();
-  var configurations = optionsParser.parse(new Options().arguments);
+  List<Map> configurations = optionsParser.parse(new Options().arguments);
   if (configurations == null) return;
+
   // Extract global options from first configuration.
   var firstConf = configurations[0];
-  var queue = new ProcessQueue(firstConf['tasks'],
-                               firstConf['progress'],
-                               startTime);
   Map<String, RegExp> selectors = firstConf['selectors'];
-  for (var conf in configurations) {
+  var maxProcesses = firstConf['tasks'];
+  var progressIndicator = firstConf['progress'];
+
+  var currentConfiguration = 0;
+  bool enqueueConfiguration(ProcessQueue queue) {
+    if (currentConfiguration == configurations.length) {
+      return false;
+    }
+
+    var conf = configurations[currentConfiguration++];
     if (selectors.containsKey('samples')) {
       queue.addTestSuite(new SamplesTestSuite(conf));
     }
@@ -65,5 +72,13 @@ main() {
     if (selectors.containsKey('leg_only')) {
       queue.addTestSuite(new LegOnlyTestSuite(conf));
     }
+
+    return true;
   }
+
+  // Start process queue.
+  var queue = new ProcessQueue(maxProcesses,
+                               progressIndicator,
+                               startTime,
+                               enqueueConfiguration);
 }