dart2js cps: Ensure parameter default values are emitted.

pkg/compiler/lib/src/js_backend/codegen/glue.dart

 // Copyright (c) 2014, 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.
 
 library code_generator_dependencies;
 
 import '../js_backend.dart';
 
 import '../../common.dart';
 import '../../common/registry.dart' show
@@ skipping 47 matching lines @@
   }
 
   reportInternalError(String message) {
     reporter.internalError(CURRENT_ELEMENT_SPANNABLE, message);
   }
 
   bool isUsedAsMixin(ClassElement classElement) {
     return classWorld.isUsedAsMixin(classElement);
   }
 
-  ConstantValue getConstantValueForVariable(VariableElement variable) {
-    return _backend.constants.getConstantValueForVariable(variable);
-  }
-
   js.Expression staticFunctionAccess(FunctionElement element) {
     return _backend.emitter.staticFunctionAccess(element);
   }
 
   js.Expression isolateStaticClosureAccess(FunctionElement element) {
     return _backend.emitter.isolateStaticClosureAccess(element);
   }
 
   js.Expression staticFieldAccess(FieldElement element) {
     return _backend.emitter.staticFieldAccess(element);
@@ skipping 202 matching lines @@
 
   bool isBoolClass(ClassElement classElement) =>
       classElement == _backend.jsBoolClass ||
       classElement == _compiler.boolClass;
 
   // TODO(sra): Should this be part of CodegenRegistry?
   void registerNativeBehavior(NativeBehavior nativeBehavior, node) {
     if (nativeBehavior == null) return;
     _enqueuer.nativeEnqueuer.registerNativeBehavior(nativeBehavior, node);
   }
+
+  ConstantValue getDefaultParameterValue(ParameterElement elem) {
+    return _backend.constants.getConstantValueForVariable(elem);
+  }
 }