Ensure we run the observable transform on PolymerElement (fixes issue 14942)

pkg/pkg.status

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # Don't run any test-like files that show up in packages directories. It
 # shouldn't be necessary to run "pub install" in these packages, but if you do
 # it shouldn't break the tests.
 */packages/*/*: Skip
 */*/packages/*/*: Skip
 */*/*/packages/*/*: Skip
@@ skipping 181 matching lines @@
 http_server/test/*: Fail, OK # Uses dart:io.
 intl/test/date_time_format_file_even_test: Fail, OK # Uses dart:io.
 intl/test/date_time_format_file_odd_test: Fail, OK # Uses dart:io.
 intl/test/find_default_locale_standalone_test: Fail, OK # Uses dart:io.
 intl/test/message_extraction/message_extraction_test: Fail, OK # Uses dart:io.
 intl/test/message_extraction/failed_extraction_test: Fail, OK # Users dart:io
 oauth2/test/authorization_code_grant_test: Fail, OK # Uses dart:io.
 oauth2/test/client_test: Fail, OK # Uses dart:io.
 oauth2/test/credentials_test: Fail, OK # Uses dart:io.
 oauth2/test/handle_access_token_response_test: Fail, OK # Uses dart:io.
-observe/test/transform_test: Fail, OK # Uses dart:io.
+observe/test/transformer_test: Fail, OK # Uses dart:io.
 path/test/io_test: Fail, OK # Uses dart:io.
 polymer/test/build/*: Fail, OK # Uses dart:io.
 watcher/test/*: Fail, OK # Uses dart:io.
 
 scheduled_test/test/descriptor/async_test: Fail # http://dartbug.com/8440
 scheduled_test/test/descriptor/directory_test: Fail # http://dartbug.com/8440
 scheduled_test/test/descriptor/file_test: Fail # http://dartbug.com/8440
 scheduled_test/test/descriptor/nothing_test: Fail # http://dartbug.com/8440
 scheduled_test/test/descriptor/pattern_test: Fail # http://dartbug.com/8440
 scheduled_test/test/scheduled_future_matchers_test: Fail # http://dartbug.com/8440
@@ skipping 107 matching lines @@
 http/test/multipart_test: StaticWarning
 http/test/request_test: StaticWarning
 http/test/streamed_request_test: StaticWarning
 intl/test/date_time_format_file_even_test: StaticWarning
 intl/test/date_time_format_file_odd_test: StaticWarning
 intl/test/date_time_format_http_request_test: StaticWarning
 intl/test/date_time_format_local_even_test: StaticWarning
 intl/test/date_time_format_local_odd_test: StaticWarning
 unittest/test/matchers_test: StaticWarning, OK # testing error creating abstract class
 unittest/test/mock_test: StaticWarning, OK # testing unimplemented members