Dartifying some IndexedDB APIs.

tests/html/utils.dart

 library TestUtils;
+import 'dart:async';
 import '../../pkg/unittest/lib/unittest.dart';
 
 /**
  * Verifies that [actual] has the same graph structure as [expected].
  * Detects cycles and DAG structure in Maps and Lists.
  */
 verifyGraph(expected, actual) {
   var eItems = [];
   var aItems = [];
 
@@ skipping 49 matching lines @@
         }
       }
       return;
     }
 
     expect(false, isTrue, reason: 'Unhandled type: $expected');
   }
 
   walk('', expected, actual);
 }
+
+void futureTest(spec, Future body()) {
+  test(spec, () {
+    expect(body(), completes);
+  });
+}
+
+/**
+ * Executes an array of test functions which return futures in parallel.
+ *
+ * This returns a future result of the last function.
+ */
+Future chainSteps(List<Function> steps) {
+  var future = steps[0](null);
+  for (var step in steps.skip(1)) {
+    future = future.then(step);
+  }
+  return future;
+}