Fix all dart:html strong mode errors except for spurious FINAL_NOT_INITIALIZED_CONSTRUCTOR warnings.

tool/input_sdk/lib/html/html_common/conversions_dart2js.dart

Index: tool/input_sdk/lib/html/html_common/conversions_dart2js.dart
diff --git a/tool/input_sdk/lib/html/html_common/conversions_dart2js.dart b/tool/input_sdk/lib/html/html_common/conversions_dart2js.dart
index 1556dc8961c1770cbba47a75bd835ba9ce549aad..b5a1064554f66a1a3824700981c4e94a0a5cf06b 100644
--- a/tool/input_sdk/lib/html/html_common/conversions_dart2js.dart
+++ b/tool/input_sdk/lib/html/html_common/conversions_dart2js.dart
@@ -91,10 +91,3 @@ Future convertNativePromiseToDartFuture(promise) {
   var newPromise = JS('', '#.then(#)["catch"](#)', promise, then, error);
   return completer.future;
 }
-
-// TODO(vsm,jacobr): We shouldn't need to expose these.
-/// Wrap a JS object with an instance of the matching dart:html class. Used only in Dartium.
-wrap_jso(jsObject) => jsObject;
-
-/// Find the underlying JS object for a dart:html Dart object.
-unwrap_jso(dartClass_instance) => dartClass_instance;