Update Timer API to take the callback as the last parameter.

tools/testing/dart/test_suite.dart

Index: tools/testing/dart/test_suite.dart
diff --git a/tools/testing/dart/test_suite.dart b/tools/testing/dart/test_suite.dart
index ea17f5dfc8b821b80e0706d852897af920b1366b..59c3cf5e7681548fefe4d741267a570c81caa62d 100644
--- a/tools/testing/dart/test_suite.dart
+++ b/tools/testing/dart/test_suite.dart
@@ -245,7 +245,7 @@ class StandardTestSuite implements TestSuite {
             }
             doDone();
           }
-          new Timer(enqueueCachedTests, 0);
+          new Timer(0, enqueueCachedTests);
         }
       }
     }
@@ -956,12 +956,12 @@ class JUnitTestSuite implements TestSuite {
 
     if (configuration['component'] != 'dartc') {
       // Do nothing.  Asynchronously report that the suite is enqueued.
-      new Timer((timerUnused){ doDone(); }, 0);
+      new Timer(0, (timerUnused){ doDone(); });
       return;
     }
     RegExp pattern = configuration['selectors']['dartc'];
     if (!pattern.hasMatch('junit_tests')) {
-      new Timer((timerUnused){ doDone(); }, 0);
+      new Timer(0, (timerUnused){ doDone(); });
       return;
     }