Fix for html_common

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 50a61f6a98b8875d1cbff73fcfa99e5ed4190193..e7f2696faf75c2a4b7d5ab9962e529f6224efd6c 100644
--- a/tool/sdk_expected_errors.txt
+++ b/tool/sdk_expected_errors.txt
@@ -322,7 +322,6 @@ severe: [INVALID_METHOD_OVERRIDE] Invalid override. The type of CssClassSetImpl.
 severe: [INVALID_METHOD_OVERRIDE] Invalid override. The type of CssClassSetImpl.expand (((String) → Iterable<dynamic>) → Iterable<dynamic>) is not a subtype of IterableBase<String>.expand (<T>((String) → Iterable<T>) → Iterable<T>). (dart:html_common/css_class_set.dart, line 63, col 3)
 severe: [INVALID_METHOD_OVERRIDE] Invalid override. The type of CssClassSetImpl.fold ((dynamic, (dynamic, String) → dynamic) → dynamic) is not a subtype of IterableBase<String>.fold (<T>(T, (T, String) → T) → T). (dart:html_common/css_class_set.dart, line 79, col 3)
 severe: [INVALID_METHOD_OVERRIDE] Invalid override. The type of CssClassSetImpl.difference ((Set<String>) → Set<String>) is not a subtype of Set<String>.difference ((Set<Object>) → Set<String>). (dart:html_common/css_class_set.dart, line 186, col 3)
-severe: [AnalyzerMessage] The getter 'userAgent' is not defined for the class 'Navigator' (dart:html_common/device.dart, line 23, col 51)
 severe: [AnalyzerMessage] The argument type 'List<Node>' cannot be assigned to the parameter type 'Iterable<Element>' (dart:html_common/filtered_element_list.dart, line 34, col 25)
 severe: [STATIC_TYPE_ERROR] Type check failed: _childNodes (List<Node>) is not of type Iterable<Element> (dart:html_common/filtered_element_list.dart, line 34, col 25)
 warning: [DOWN_CAST_COMPOSITE] new List.from(_elementIterable).map((e) => e.style) (Iterable<dynamic>) will need runtime check to cast to type Iterable<CssStyleDeclaration> (dart:html, line 839, col 46)