Store constant variable initializers in elements.

pkg/compiler/lib/src/dart_backend/backend.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.
 
 part of dart_backend;
 
 // TODO(ahe): This class is simply wrong.  This backend should use
 // elements when it can, not AST nodes.  Perhaps a [Map<Element,
 // TreeElements>] is what is needed.
 class ElementAst {
@@ skipping 455 matching lines @@
   ConstantValue getConstantValue(ConstantExpression expression) {
     return constantCompiler.getConstantValue(expression);
   }
 
   @override
   ConstantValue getConstantValueForVariable(VariableElement element) {
     return constantCompiler.getConstantValueForVariable(element);
   }
 
   @override
-  ConstantExpression getConstantForVariable(VariableElement element) {
-    return constantCompiler.getConstantForVariable(element);
-  }
-
-  @override
   ConstantExpression getConstantForNode(Node node, TreeElements elements) {
     return constantCompiler.getConstantForNode(node, elements);
   }
 
   @override
   ConstantValue getConstantValueForNode(Node node, TreeElements elements) {
     return getConstantValue(
         constantCompiler.getConstantForNode(node, elements));
   }
 
   @override
   ConstantValue getConstantValueForMetadata(MetadataAnnotation metadata) {
     return getConstantValue(metadata.constant);
   }
 
   @override
   ConstantExpression compileConstant(VariableElement element) {
     return measure(() {
       return constantCompiler.compileConstant(element);
     });
   }
 
   @override
   void evaluate(ConstantExpression constant) {
     return measure(() {
       return constantCompiler.evaluate(constant);
     });
   }
 
-  void compileVariable(VariableElement element) {
-    measure(() {
-      constantCompiler.compileVariable(element);
+  @override
+  ConstantExpression compileVariable(VariableElement element) {
+    return measure(() {
+      return constantCompiler.compileVariable(element);
     });
   }
 
   @override
   ConstantExpression compileNode(Node node, TreeElements elements,
       {bool enforceConst: true}) {
     return measure(() {
       return constantCompiler.compileNodeWithDefinitions(node, elements,
           isConst: enforceConst);
     });
   }
 
   @override
   ConstantExpression compileMetadata(
       MetadataAnnotation metadata, Node node, TreeElements elements) {
     return measure(() {
       return constantCompiler.compileMetadata(metadata, node, elements);
     });
   }
 
   // TODO(johnniwinther): Remove this when values are computed from the
   // expressions.
   @override
   void copyConstantValues(DartConstantTask task) {
     constantCompiler.constantValueMap
         .addAll(task.constantCompiler.constantValueMap);
   }
 }