dart2js_native tests: Migrate 'native STRING' to JS-calls

tests/compiler/dart2js_native/native_class_inheritance3_frog_test.dart

Index: tests/compiler/dart2js_native/native_class_inheritance3_frog_test.dart
diff --git a/tests/compiler/dart2js_native/native_class_inheritance3_frog_test.dart b/tests/compiler/dart2js_native/native_class_inheritance3_frog_test.dart
index 8f900ef97dc53212a5571af6c9f73cf4cb6e412d..af5a8e3df43c5a00d9209c2f4d1fe61924dfcfe5 100644
--- a/tests/compiler/dart2js_native/native_class_inheritance3_frog_test.dart
+++ b/tests/compiler/dart2js_native/native_class_inheritance3_frog_test.dart
@@ -30,40 +30,43 @@ makeB2() native;
 
 makeObject() native;
 
-void setup() native """
-// This code is all inside 'setup' and so not accessible from the global scope.
-function inherits(child, parent) {
-  if (child.prototype.__proto__) {
-    child.prototype.__proto__ = parent.prototype;
-  } else {
-    function tmp() {};
-    tmp.prototype = parent.prototype;
-    child.prototype = new tmp();
-    child.prototype.constructor = child;
+void setup() {
+  JS('', r"""
+(function(){
+  // This code is inside 'setup' and so not accessible from the global scope.
+  function inherits(child, parent) {
+    if (child.prototype.__proto__) {
+      child.prototype.__proto__ = parent.prototype;
+    } else {
+      function tmp() {};
+      tmp.prototype = parent.prototype;
+      child.prototype = new tmp();
+      child.prototype.constructor = child;
+    }
   }
-}
-function A1(){}
-function B1(){}
-inherits(B1, A1);
+  function A1(){}
+  function B1(){}
+  inherits(B1, A1);
 
-makeA1 = function(){return new A1};
-makeB1 = function(){return new B1};
+  makeA1 = function(){return new A1()};
+  makeB1 = function(){return new B1()};
 
-function A2(){}
-function B2(){}
-inherits(B2, A2);
-A2.prototype.foo = function(a){return 'A2.foo(' + a  + ')';}
+  function A2(){}
+  function B2(){}
+  inherits(B2, A2);
+  A2.prototype.foo = function(a){return 'A2.foo(' + a  + ')';};
 
-makeA2 = function(){return new A2};
-makeB2 = function(){return new B2};
+  makeA2 = function(){return new A2()};
+  makeB2 = function(){return new B2()};
 
-makeObject = function(){return new Object};
+  makeObject = function(){return new Object()};
 
-self.nativeConstructor(A1);
-self.nativeConstructor(A2);
-self.nativeConstructor(B1);
-self.nativeConstructor(B2);
-""";
+  self.nativeConstructor(A1);
+  self.nativeConstructor(A2);
+  self.nativeConstructor(B1);
+  self.nativeConstructor(B2);
+})()""");
+}
 
 main() {
   nativeTesting();