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

tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart

Index: tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart
diff --git a/tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart b/tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart
index c6ae9c72e2fb75a87ab70f54ef856de338bb1dee..edbc3b3845240725ade3738e856f44c837488296 100644
--- a/tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart
+++ b/tests/compiler/dart2js_native/native_field_rename_2_frog_test.dart
@@ -22,9 +22,11 @@ class B implements I {
 }
 
 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;