Store constant variable initializers in elements.

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 '../../common.dart';
 import '../../common/codegen.dart' show CodegenRegistry;
 import '../../compiler.dart' show Compiler;
 import '../../constants/values.dart';
@@ skipping 251 matching lines @@
       classElement == _helpers.jsBoolClass ||
       classElement == _compiler.coreClasses.boolClass;
 
   // TODO(sra,johnniwinther): 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);
+    return _backend.constants.getConstantValue(elem.constant);
   }
 
   TypeMask extendMaskIfReachesAll(Selector selector, TypeMask mask) {
     return _compiler.world.extendMaskIfReachesAll(selector, mask);
   }
 
   FunctionElement get closureFromTearOff => _backend.helpers.closureFromTearOff;
 
   js.Name registerOneShotInterceptor(Selector selector) {
     return _backend.registerOneShotInterceptor(selector);
   }
 
   bool mayGenerateInstanceofCheck(DartType type) {
     return _backend.mayGenerateInstanceofCheck(type);
   }
 
   bool methodUsesReceiverArgument(FunctionElement function) {
     assert(isInterceptedMethod(function));
     ClassElement class_ = function.enclosingClass.declaration;
     return isInterceptorClass(class_) || isUsedAsMixin(class_);
   }
 }