Handle const loop variable.

pkg/compiler/lib/src/resolution/members.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.
 
 library dart2js.resolution.members;
 
 import '../common.dart';
 import '../common/names.dart' show
     Selectors;
 import '../common/resolution.dart' show
@@ skipping 108 matching lines @@
   /// `prefix.Class.staticMethod()`.
   bool sendIsMemberAccess = false;
 
   StatementScope statementScope;
   int allowedCategory = ElementCategory.VARIABLE | ElementCategory.FUNCTION
       | ElementCategory.IMPLIES_TYPE;
 
   /// When visiting the type declaration of the variable in a [ForIn] loop,
   /// the initializer of the variable is implicit and we should not emit an
   /// error when verifying that all final variables are initialized.
-  bool allowFinalWithoutInitializer = false;
+  bool inLoopVariable = false;
 
   /// The nodes for which variable access and mutation must be registered in
   /// order to determine when the static type of variables types is promoted.
   Link<Node> promotionScope = const Link<Node>();
 
   bool isPotentiallyMutableTarget(Element target) {
     if (target == null) return false;
     return (target.isVariable || target.isParameter) &&
       !(target.isFinal || target.isConst);
   }
@@ skipping 4240 matching lines @@
     visitLoopBodyIn(node, node.body, blockScope);
     return const NoneResult();
   }
 
   void visitForInDeclaredIdentifierIn(
       Node declaration,
       ForIn node,
       Scope blockScope) {
     LibraryElement library = enclosingElement.library;
 
-    bool oldAllowFinalWithoutInitializer = allowFinalWithoutInitializer;
-    allowFinalWithoutInitializer = true;
+    bool oldAllowFinalWithoutInitializer = inLoopVariable;
+    inLoopVariable = true;
     visitIn(declaration, blockScope);
-    allowFinalWithoutInitializer = oldAllowFinalWithoutInitializer;
+    inLoopVariable = oldAllowFinalWithoutInitializer;
 
     Send send = declaration.asSend();
     VariableDefinitions variableDefinitions =
         declaration.asVariableDefinitions();
     Element loopVariable;
     Selector loopVariableSelector;
     if (send != null) {
       loopVariable = registry.getDefinition(send);
       Identifier identifier = send.selector.asIdentifier();
       if (identifier == null) {
@@ skipping 447 matching lines @@
     }
     return const NoneResult();
   }
 }
 
 /// Looks up [name] in [scope] and unwraps the result.
 Element lookupInScope(DiagnosticReporter reporter, Node node,
                       Scope scope, String name) {
   return Elements.unwrap(scope.lookup(name), reporter, node);
 }