Make ClassNode visit type parameters in visitChildren

tests/compiler/dart2js/unparser_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.
 
 #import('dart:uri');
 #import('parser_helper.dart');
 #import('mock_compiler.dart');
 #import("../../../lib/compiler/compiler.dart");
 #import("../../../lib/compiler/implementation/dart_backend/dart_backend.dart");
 #import("../../../lib/compiler/implementation/elements/elements.dart");
@@ skipping 528 matching lines @@
 }
 ''';
   var expectedResult =
     'class T{}class B<T>{}class A<T> extends B<T>{T f;}'
     'class p_T{}class p_B<p_T>{}class p_A<p_T> extends p_B<p_T>{p_T f;}'
     'main(){new p_A<int>().f; new p_T(); new A<int>().f; new T();}';
   testDart2DartWithLibrary(mainSrc, librarySrc,
       (String result) { Expect.equals(expectedResult, result); });
 }
 
+testClassTypeArgumentBound() {
+  var librarySrc = '''
+#library('mylib');
+
+interface I {}
+class A<T extends I> {}
+
+''';
+  var mainSrc = '''
+#import('mylib.dart', prefix: 'mylib');
+
+interface I {}
+class A<T extends I> {}
+
+main() {
+  new A();
+  new mylib.A();
+}
+''';
+  var expectedResult =
+    'interface I{}'
+    'class A<T extends I>{}'
+    'interface p_I{}'
+    'class p_A<p_T extends p_I>{}'
+    'main(){new p_A(); new A();}';
+  testDart2DartWithLibrary(mainSrc, librarySrc,
+      (String result) { Expect.equals(expectedResult, result); });
+}
+
 main() {
   testSignedConstants();
   testGenericTypes();
   testForLoop();
   testEmptyList();
   testClosure();
   testIndexedOperatorDecl();
   testNativeMethods();
   testPrefixIncrements();
   testConstModifier();
@@ skipping 12 matching lines @@
   testNoConflictSendsRename();
   testConflictLibraryClassRename();
   testDefaultClassWithArgs();
   testClassExtendsWithArgs();
   testStaticInvocation();
   testLibraryGetSet();
   testFieldTypeOutput();
   testDefaultClassNamePlaceholder();
   testFactoryRename();
   testTypeVariablesAreRenamed();
+  testClassTypeArgumentBound();
 }