dart2js: support checked setters in startup-emitter.

pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart

Index: pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart
diff --git a/pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart b/pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart
index 43edaac419e1530c77d5c09c715b4c8cd4cf6bee..2b40240d3093c5bd3e2623b48907d116d20ca5b9 100644
--- a/pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart
+++ b/pkg/compiler/lib/src/js_emitter/startup_emitter/fragment_emitter.dart
@@ -594,14 +594,15 @@ class FragmentEmitter {
   //    needed.
   js.Expression emitPrototype(Class cls) {
     Iterable<Method> methods = cls.methods;
+    Iterable<Method> checkedSetters = cls.checkedSetters;
     Iterable<Method> isChecks = cls.isChecks;
     Iterable<Method> callStubs = cls.callStubs;
     Iterable<Method> typeVariableReaderStubs = cls.typeVariableReaderStubs;
     Iterable<Method> noSuchMethodStubs = cls.noSuchMethodStubs;
     Iterable<Method> gettersSetters = generateGettersSetters(cls);
     Iterable<Method> allMethods =
-        [methods, isChecks, callStubs, typeVariableReaderStubs,
-    noSuchMethodStubs, gettersSetters].expand((x) => x);
+        [methods, checkedSetters, isChecks, callStubs, typeVariableReaderStubs,
+         noSuchMethodStubs, gettersSetters].expand((x) => x);
 
     List<js.Property> properties = <js.Property>[];