Use entities in class_stub_generator.

pkg/compiler/lib/src/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.
 
 library js_backend.namer;
 
 import 'dart:collection' show HashMap;
 
 import 'package:js_runtime/shared/embedded_names.dart' show JsGetName;
 
@@ skipping 1479 matching lines @@
         // [staticStateHolder].
         !element.isAccessor &&
             !element.isClass &&
             !element.isTypedef &&
             !element.isConstructor &&
             !element.isFunction &&
             !element.isLibrary;
   }
 
   /// Returns [staticStateHolder] or one of [reservedGlobalObjectNames].
+  // TODO(johnniwinther): Verify that the implementation can be changed to
+  // `globalObjectForLibrary(element.library)`.
+  String globalObjectForMethod(MethodElement element) =>
+      globalObjectFor(element);
+
+  /// Returns [staticStateHolder] or one of [reservedGlobalObjectNames].
   String globalObjectFor(Element element) {
     if (_isPropertyOfStaticStateHolder(element)) return staticStateHolder;
-    LibraryElement library = element.library;
+    return globalObjectForLibrary(element.library);
+  }
+
+  /// Returns the [reservedGlobalObjectNames] for [library].
+  String globalObjectForLibrary(LibraryElement library) {
     if (library == helpers.interceptorsLibrary) return 'J';
     if (library.isInternalLibrary) return 'H';
     if (library.isPlatformLibrary) {
       if ('${library.canonicalUri}' == 'dart:html') return 'W';
       return 'P';
     }
     return userGlobalObjects[
         library.libraryOrScriptName.hashCode % userGlobalObjects.length];
   }
 
@@ skipping 675 matching lines @@
   void addSuggestion(String original, String suggestion) {
     assert(!_suggestedNames.containsKey(original));
     _suggestedNames[original] = suggestion;
   }
 
   bool hasSuggestion(String original) => _suggestedNames.containsKey(original);
   bool isSuggestion(String candidate) {
     return _suggestedNames.containsValue(candidate);
   }
 }