Make parts hermetic, fixes #531

tool/sdk_expected_errors.txt

Index: tool/sdk_expected_errors.txt
diff --git a/tool/sdk_expected_errors.txt b/tool/sdk_expected_errors.txt
index c2c3795173dd25c918f57b8feae1c4767e2ae867..14841d601e1a2abfa34c29dbcca7f0ece21b5018 100644
--- a/tool/sdk_expected_errors.txt
+++ b/tool/sdk_expected_errors.txt
@@ -3,6 +3,12 @@
 [error] Missing concrete implementation of 'String.==' (dart:_interceptors/js_string.dart, line 14, col 7)
 [error] Type check failed: (_BroadcastSubscription<T> subscription) {subscription._close();} ((_BroadcastSubscription<T>) → void) is not of type (_BufferingStreamSubscription<T>) → void (dart:async/broadcast_stream_controller.dart, line 371, col 24)
 [error] Annotation can be only constant variable or constant constructor invocation (dart:core/stacktrace.dart, line 27, col 3)
+[error] The part was not supplied as an input to the compiler. (dart:html_common/conversions.dart, line 1, col 1)
+[error] The part was not supplied as an input to the compiler. (dart:html_common/conversions_dart2js.dart, line 1, col 1)
+[error] The part was not supplied as an input to the compiler. (dart:html_common/css_class_set.dart, line 1, col 1)
+[error] The part was not supplied as an input to the compiler. (dart:html_common/device.dart, line 1, col 1)
+[error] The part was not supplied as an input to the compiler. (dart:html_common/filtered_element_list.dart, line 1, col 1)
+[error] The part was not supplied as an input to the compiler. (dart:html_common/lists.dart, line 1, col 1)
 [warning] Unsound implicit cast from dynamic to List<String> (dart:_debugger, line 25, col 5)
 [warning] Unsound implicit cast from dynamic to List<String> (dart:_isolate_helper, line 839, col 37)
 [warning] Unsound implicit cast from dynamic to List<String> (dart:_isolate_helper, line 886, col 11)