Test whether DDC sdk is up-to-date

pkg/dev_compiler/lib/js/es6/dart_sdk.js

Index: pkg/dev_compiler/lib/js/es6/dart_sdk.js
diff --git a/pkg/dev_compiler/lib/js/es6/dart_sdk.js b/pkg/dev_compiler/lib/js/es6/dart_sdk.js
index 02d99d240f95b7c78f8482491e40a5d9c1b28572..cb578cd2b6cbc3d53bb60d72759ace13173a546b 100644
--- a/pkg/dev_compiler/lib/js/es6/dart_sdk.js
+++ b/pkg/dev_compiler/lib/js/es6/dart_sdk.js
@@ -116482,22 +116482,6 @@ dart.setSignature(web_sql.SqlTransaction, {
   methods: () => ({[$executeSql]: dart.fnType(dart.void, [core.String], [core.List, web_sql.SqlStatementCallback, web_sql.SqlStatementErrorCallback])})
 });
 dart.registerExtension("SQLTransaction", web_sql.SqlTransaction);
-nativewrappers.NativeFieldWrapperClass1 = class NativeFieldWrapperClass1 extends core.Object {};
-(nativewrappers.NativeFieldWrapperClass1.new = function() {
-}).prototype = nativewrappers.NativeFieldWrapperClass1.prototype;
-dart.addTypeTests(nativewrappers.NativeFieldWrapperClass1);
-nativewrappers.NativeFieldWrapperClass2 = class NativeFieldWrapperClass2 extends core.Object {};
-(nativewrappers.NativeFieldWrapperClass2.new = function() {
-}).prototype = nativewrappers.NativeFieldWrapperClass2.prototype;
-dart.addTypeTests(nativewrappers.NativeFieldWrapperClass2);
-nativewrappers.NativeFieldWrapperClass3 = class NativeFieldWrapperClass3 extends core.Object {};
-(nativewrappers.NativeFieldWrapperClass3.new = function() {
-}).prototype = nativewrappers.NativeFieldWrapperClass3.prototype;
-dart.addTypeTests(nativewrappers.NativeFieldWrapperClass3);
-nativewrappers.NativeFieldWrapperClass4 = class NativeFieldWrapperClass4 extends core.Object {};
-(nativewrappers.NativeFieldWrapperClass4.new = function() {
-}).prototype = nativewrappers.NativeFieldWrapperClass4.prototype;
-dart.addTypeTests(nativewrappers.NativeFieldWrapperClass4);
 dart.trackLibraries("dart_sdk", {
   "dart:_runtime": dart,
   "dart:_debugger": _debugger,