Test changes accompanying Dartium indexed DB fixes

tests/html/indexeddb_4_test.dart

 library IndexedDB4Test;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import 'dart:async';
 import 'dart:html' as html;
 import 'dart:indexed_db';
 
 // Test for KeyRange and Cursor.
 
 const String DB_NAME = 'Test4';
@@ skipping 63 matching lines @@
   });
 }
 
 main() {
   useHtmlConfiguration();
 
   // Don't bother with these tests if it's unsupported.
   // Support is tested in indexeddb_1_test
   if (IdbFactory.supported) {
     var db;
-    test('prepare', () {
-      return setupDb().then((result) {
-          db = result;
-        });
+    setUp(() {
+      if (db == null) {
+        return setupDb().then((result) {
+            db = result;
+          });
+      }
     });
-
-    test('only1', () => testRange(db, new KeyRange.only(55), 55, 55));
-
     test('only1', () => testRange(db, new KeyRange.only(55), 55, 55));
     test('only2', () => testRange(db, new KeyRange.only(100), null, null));
     test('only3', () => testRange(db, new KeyRange.only(-1), null, null));
 
     test('lower1', () =>
         testRange(db, new KeyRange.lowerBound(40), 40, 99));
     // OPTIONALS lower2() => testRange(db, new KeyRange.lowerBound(40, open: true), 41, 99);
     test('lower2', () =>
         testRange(db, new KeyRange.lowerBound(40, true), 41, 99));
     // OPTIONALS lower3() => testRange(db, new KeyRange.lowerBound(40, open: false), 40, 99);
@@ skipping 21 matching lines @@
 
     bound4() =>
         // OPTIONALS testRange(db, new KeyRange.bound(20, 30, lowerOpen: true),
         testRange(db, new KeyRange.bound(20, 30, true), 21, 30);
 
     bound5() =>
         // OPTIONALS testRange(db, new KeyRange.bound(20, 30, lowerOpen: true, upperOpen: true),
         testRange(db, new KeyRange.bound(20, 30, true, true), 21, 29);
   }
 }