Improve type information and minor clean up

pkg/analyzer/lib/src/context/cache.dart

 // Copyright (c) 2015, 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 analyzer.src.context.cache;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/src/dart/element/element.dart'
@@ skipping 161 matching lines @@
    *
    * It does not update the cache, if the corresponding [CacheEntry] does not
    * exist, then the default value is returned.
    */
   Object/*=V*/ getValue/*<V>*/(
       AnalysisTarget target, ResultDescriptor/*<V>*/ result) {
     CacheEntry entry = get(target);
     if (entry == null) {
       return result.defaultValue;
     }
-    return entry.getValue(result) as Object/*=V*/;
+    return entry.getValue(result);
   }
 
   /**
    * Return an iterator returning all of the map entries mapping targets to
    * cache entries. If the [context] is not `null`, then only entries that are
    * owned by the given context will be returned.
    */
   MapIterator<AnalysisTarget, CacheEntry> iterator(
       {InternalAnalysisContext context: null}) {
     List<Map<AnalysisTarget, CacheEntry>> maps =
@@ skipping 1086 matching lines @@
   void resultAccessed(TargetedResult result) {}
 
   @override
   List<TargetedResult> resultStored(TargetedResult newResult, newValue) {
     return TargetedResult.EMPTY_LIST;
   }
 
   @override
   void targetRemoved(AnalysisTarget target) {}
 }