Add @JSName annotation for native fields and methods - second try.

tests/compiler/dart2js_native/native_field_rename_1_frog_test.dart

Index: tests/compiler/dart2js_native/native_field_rename_1_frog_test.dart
diff --git a/tests/compiler/dart2js_native/native_field_rename_1_frog_test.dart b/tests/compiler/dart2js_native/native_field_rename_1_frog_test.dart
index 112854f27085cba0cd73c09544031f501e9f7f8b..317ce350abc6fc479bb2cae4b07ce282e7dcbd62 100644
--- a/tests/compiler/dart2js_native/native_field_rename_1_frog_test.dart
+++ b/tests/compiler/dart2js_native/native_field_rename_1_frog_test.dart
@@ -18,10 +18,12 @@ class B {
 }
 
 class X native "*X" {
-  int native_key_method() native 'key';
+  @JSName('key')
+  int native_key_method() native;
   // This should cause B.key to be renamed, but not A.key.
 
-  int key() native 'key';
+  @JSName('key')
+  int key() native;
 }
 
 A makeA() native;