Copy lib/dom tests that use dart:html to lib/html.

tests/dom/cache_test.dart

-#library('CacheTest');
-#import('../../lib/unittest/unittest.dart');
-#import('../../lib/unittest/html_config.dart');
-#import('dart:html');
-
-main() {
-  useHtmlConfiguration();
-  test('ApplicationCache', () {
-    DOMApplicationCache appCache = window.applicationCache;
-    Expect.equals("UNCACHED", cacheStatusToString(appCache.status));
-  });
-}
-
-String cacheStatusToString(int status) {
-  switch (status) {
-    case DOMApplicationCache.UNCACHED: // UNCACHED == 0
-      return 'UNCACHED';
-    case DOMApplicationCache.IDLE: // IDLE == 1
-      return 'IDLE';
-    case DOMApplicationCache.CHECKING: // CHECKING == 2
-      return 'CHECKING';
-    case DOMApplicationCache.DOWNLOADING: // DOWNLOADING == 3
-      return 'DOWNLOADING';
-    case DOMApplicationCache.UPDATEREADY:  // UPDATEREADY == 4
-      return 'UPDATEREADY';
-    case DOMApplicationCache.OBSOLETE: // OBSOLETE == 5
-      return 'OBSOLETE';
-    default:
-      return 'UNKNOWN CACHE STATUS';
-  };
-}