Remove support for interface in dart2js.

tests/compiler/dart2js/deprecated_features_test.dart

 // Copyright (c) 2012, 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 deprecated language features are diagnosed correctly.
 
 import "package:expect/expect.dart";
 import 'dart:async';
 import 'dart:uri';
 
@@ skipping 25 matching lines @@
 
   String code = deprecatedFutureValue(
       compile(new Uri.fromComponents(scheme: 'main'),
               new Uri.fromComponents(scheme: 'lib', path: '/'),
               new Uri.fromComponents(scheme: 'package', path: '/'),
               provider, handler));
   if (code == null) {
     throw 'Compilation failed: ${messages}';
   }
   Expect.stringEquals(
-      // This string is comprised of lines of the following format:
+      // This string is composed of lines of the following format:
       //
       // offset<source>:path:kind: message
       //
       // "offset" is the character offset from the beginning of TEST_SOURCE.
       // "source" is the substring of TEST_SOURCE that the compiler is
       // indicating as erroneous.
       // "path" is the URI path.
       // "kind" is the result of calling toString on a [Diagnostic] object.
       // "message" is the expected message as a [String].  This is a
       // short-term solution and should eventually changed to include
       // a symbolic reference to a MessageKind.
       "0<#library('test');>::${deprecatedMessage('# tags')}\n"
-      "38<interface>::${deprecatedMessage('interface declarations')}\n"
       "19<part 'part.dart';>::${deprecatedMessage('missing part-of tag')}\n"
       "0<>:/part.dart:info: Note: This file has no part-of tag, but it is being"
       " used as a part.\n"
-      "163<Fisk>::${deprecatedMessage('interface factories')}\n"
-
-      // TODO(ahe): Should be <Fisk.hest>.
-      "183<Fisk>::${deprecatedMessage('interface factories')}\n"
 
       // TODO(ahe): Should be <bar>.
-      "109<Foo>::${deprecatedMessage('conflicting constructor')}\n"
+      "52<Foo>::${deprecatedMessage('conflicting constructor')}\n"
 
-      "129<bar>::info: This member conflicts with a constructor.\n"
-      "205<()>::${deprecatedMessage('getter parameters')}\n",
+      "72<bar>::info: This member conflicts with a constructor.\n"
+      "103<()>::${deprecatedMessage('getter parameters')}\n",
       messages.toString());
 }
 
 deprecatedMessage(feature) {
   return
     "warning: Warning: deprecated language feature, $feature"
     ", will be removed in a future Dart milestone.";
 }
 
 const Map<String, String> TEST_SOURCE =
   const <String, String>{ '': """
 #library('test');
 
 part 'part.dart';
 
-interface Fisk default Foo {
-  Fisk();
-  Fisk.hest();
-}
-
 class Foo {
   Foo.bar();
   static bar() => new Foo.bar();
-  factory Fisk() {}
-  factory Fisk.hest() {}
   get x() => null;
 }
 
 main() {
   var a = Foo.bar();
   var b = new Foo.bar();
-  new Fisk();
-  new Fisk.hest();
 }
 """,
     // TODO(ahe): Why isn't this 'part.dart'? Why the leading slash?
     '/part.dart': '',
   };