Fix for a memory leak in CacheFlushManager.

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:collection';
 
 import 'package:analyzer/src/generated/engine.dart'
     show AnalysisEngine, CacheState, InternalAnalysisContext, RetentionPriority;
@@ skipping 639 matching lines @@
    */
   List<TargetedResult> madeIdle() {
     maxSize = maxIdleSize;
     return flushToSize();
   }
 
   /**
    * Records that the given [result] was just read from the cache.
    */
   void resultAccessed(TargetedResult result) {
+    if (maxSize <= 0) {
+      return;
+    }
     if (recentlyUsed.remove(result)) {
       recentlyUsed.add(result);
     }
   }
 
   /**
    * Records that the given [newResult] and [newValue] were stored to the cache.
    * Returns [TargetedResult]s that should be flushed from the cache.
    */
   List<TargetedResult> resultStored(TargetedResult newResult, T newValue) {
+    if (maxSize <= 0) {
+      return TargetedResult.EMPTY_LIST;
+    }
     if (!recentlyUsed.remove(newResult)) {
       int size = policy.measure(newValue);
       resultSizeMap[newResult] = size;
       currentSize += size;
     }
     recentlyUsed.add(newResult);
     return flushToSize();
   }
 
   /**
@@ skipping 292 matching lines @@
 class UniversalCachePartition extends CachePartition {
   /**
    * Initialize a newly created cache partition, belonging to the given
    * [context].
    */
   UniversalCachePartition(InternalAnalysisContext context) : super(context);
 
   @override
   bool isResponsibleFor(AnalysisTarget target) => true;
 }