Type annotations instead of closure comments.

test/codegen/closure.dart

 library test;
 import 'dart:js';
 
+List/*<T>*/ generic_function/*<T>*/(List/*<T>*/ items, dynamic/*=T*/ seed) {
+  var strings = items.map((i) => "$i").toList();
+  return items;
+}
 
 typedef void Callback({int i});
 
 class Foo<T> {
   final int i;
   bool b;
   String s;
   T v;
 
   Foo(this.i, this.v);
 
   factory Foo.build() => new Foo(1, null);
 
   untyped_method(a, b) {}
-  
+
   T pass(T t) => t;
 
   String typed_method(
       Foo foo, List list,
       int i, num n, double d, bool b, String s,
       JsArray a, JsObject o, JsFunction f) {
     return '';
   }
 
-  optional_params(a, [b, c]) {}
+  optional_params(a, [b, int c]) {}
 
-  static named_params(a, {b, c}) {}
+  static named_params(a, {b, int c}) {}
 
   nullary_method() {}
 
   function_params(int f(x, [y]), g(x, {String y, z}), Callback cb) {
     cb(i: i);
   }
 
+  run(List a, String b, List c(String d), List<int> e(f(g)), {Map<Map, Map> h}) {}
+
   String get prop => null;
   set prop(String value) {}
 
   static String get staticProp => null;
   static set staticProp(String value) {}
 
   static const String some_static_constant = "abc";
   static final String some_static_final = "abc";
   static String some_static_var = "abc";
 }
 
 class Bar {}
 
 class Baz extends Foo<int> with Bar {
   Baz(int i) : super(i, 123);
 }
 
 void main(args) {}
 
 const String some_top_level_constant = "abc";
 final String some_top_level_final = "abc";
-String some_top_level_var = "abc";
+String some_top_level_var = "abc";