Patch refactoring.

lib/compiler/implementation/js_backend/namer.dart

 // Copyright (c) 2011, 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.
 
 /**
  * Assigns JavaScript identifiers to Dart variables, class-names and members.
  */
 class Namer {
   final Compiler compiler;
 
   static Set<String> _jsReserved = null;
   Set<String> get jsReserved {
     if (_jsReserved === null) {
       _jsReserved = new Set<String>();
       _jsReserved.addAll(JsNames.javaScriptKeywords);
       _jsReserved.addAll(JsNames.reservedPropertySymbols);
     }
     return _jsReserved;
   }
 
+  /**
+   * Map from top-level or static elements to their unique identifiers provided
+   * by [getName].
+   *
+   * Invariant: Keys must be declaration elements.
+   */
   final Map<Element, String> globals;
   final Map<String, int> usedGlobals;
   final Map<String, LibraryElement> shortPrivateNameOwners;
 
   final Map<Constant, String> constantNames;
 
   Namer(this.compiler)
       : globals = new Map<Element, String>(),
         usedGlobals = new Map<String, int>(),
         shortPrivateNameOwners = new Map<String, LibraryElement>(),
@@ skipping 205 matching lines @@
         return getterName(element.getLibrary(), element.name);
       } else if (element.kind == ElementKind.SETTER) {
         return setterName(element.getLibrary(), element.name);
       } else if (element.kind == ElementKind.FIELD) {
         return instanceFieldName(element.getLibrary(), element.name);
       } else {
         compiler.internalError('getName for bad kind: ${element.kind}',
                                node: element.parseNode(compiler));
       }
     } else {
+      // Use declaration element to ensure invariant on [globals].
+      element = element.declaration;
+
       // Dealing with a top-level or static element.
       String cached = globals[element];
       if (cached !== null) return cached;
 
       String guess = _computeGuess(element);
       ElementKind kind = element.kind;
       if (kind === ElementKind.VARIABLE ||
           kind === ElementKind.PARAMETER) {
         // The name is not guaranteed to be unique.
         return guess;
@@ skipping 46 matching lines @@
   }
 
   String safeName(String name) {
     if (jsReserved.contains(name) || name.startsWith('\$')) {
       name = "\$$name";
       assert(!jsReserved.contains(name));
     }
     return name;
   }
 }