Change dart2js_foreign suite to use metadata.

dart/tests/compiler/dart2js_foreign/native_call_arity1_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.
 
 // Test that native methods with unnamed* optional arguments are called with the
 // number of arguments in the call site.  This is necessary because native
 // methods can dispatch on the number of arguments.  Passing null or undefined
 // as the last argument is not the same as passing one fewer argument.
 //
 // * Named arguments are passed in the correct position, so require preceding
 // arguments to be passed.
 
-class A native "*A" {
-  int foo(int x) native;
+@native("*A")

[sra1, 2012/08/21 00:56:14]

@native_type_tag("*A")
@nativeTypeTag("*A")

The class is a native class identified by this type tag.

Also on classes:

@nativeException

The class might be thrown by calls to native code so you can't tree-shake it. 
In dart:html there is no way for us to tell which exceptions are thrown by which
methods.  It is declared in the IDL but there is no enforcement so I don't
believe the types.

+class A  {
+  @native int foo(int x);
 }
 
-class B native "*B" {
-  int foo([x, y, z]) native;
+@native("*B")
+class B  {
+  @native int foo([x, y, z]);
 }
 
 // TODO(sra): Add a case where the parameters have default values.  Wait until
 // dart:dom_deprecated / dart:html need non-null default values.
 
-A makeA() native { return new A(); }
-B makeB() native { return new B(); }
+@native A makeA() { return new A(); }
+@native B makeB() { return new B(); }
 
-void setup() native """
+@native("""

[sra1, 2012/08/21 00:56:14]

@native_body

Although I would like to deprecate this, it is difficult to see how you could
conveniently write these tests.
Most remaining cases in dart:html can be rewritten to avoid this case.

 function A() {}
 A.prototype.foo = function () { return arguments.length; };
 
 function B() {}
 B.prototype.foo = function () { return arguments.length; };
 
 makeA = function(){return new A;};
 makeB = function(){return new B;};
-""";
+""")
+void setup();
 
 
 testDynamicContext() {
   var things = [makeA(), makeB()];
   var a = things[0];
   var b = things[1];
 
   Expect.throws(() => a.foo());
   Expect.equals(1, a.foo(10));
   Expect.throws(() => a.foo(10, 20));
@@ skipping 28 matching lines @@
   Expect.equals(2, b.foo(y: 20));
   Expect.equals(3, b.foo(z: 30));
   Expect.throws(() => b.foo(10, 20, 30, 40));
 }
 
 main() {
   setup();
   testDynamicContext();
   testStaticContext();
 }