Revert "Revert "Use interceptor convention for methods declared on native classes.""

tests/compiler/dart2js_native/native_call_arity2_frog_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // This is a similar test to NativeCallArity1FrogTest, but makes sure
 // that subclasses also get the right number of arguments.
 
 class A native "*A" {
   int foo([x, y]) native;
 }
 
 class B extends A native "*B" {
   int foo([x, y]) native;
 }
 
-A makeA() native { return new A(); }
-B makeB() native { return new B(); }
+makeA() native;
+makeB() native;
 
 void setup() native """
 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 A() {}
 A.prototype.foo = function () { return arguments.length; };
 
 function B() {}
 B.prototype.foo = function () { return arguments.length; };
 inherits(B, A);
 
 makeA = function(){return new A;};
 makeB = function(){return new B;};
 """;
 
-
 testDynamicContext() {
   var things = [makeA(), makeB()];
   var a = things[0];
   var b = things[1];
 
   Expect.equals(0, a.foo());
   Expect.equals(1, a.foo(10));
   Expect.equals(2, a.foo(10, 20));
   Expect.throws(() => a.foo(10, 20, 30));
 
@@ skipping 32 matching lines @@
   Expect.equals(1, b.foo(10));
   Expect.equals(2, b.foo(null, 20));
   Expect.throws(() => b.foo(10, 20, 30));
 }
 
 main() {
   setup();
   testDynamicContext();
   testStaticContext();
 }