Dispose private cache partition on AnalysisContext.dispose().

pkg/analyzer/lib/src/context/context.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.context;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/instrumentation/instrumentation.dart';
@@ skipping 660 matching lines @@
 
   @override
   void dispose() {
     _disposed = true;
     for (List<PendingFuture> pendingFutures in _pendingFutureTargets.values) {
       for (PendingFuture pendingFuture in pendingFutures) {
         pendingFuture.forciblyComplete();
       }
     }
     _pendingFutureTargets.clear();
+    _privatePartition.dispose();
   }
 
   @override
   List<CompilationUnit> ensureResolvedDartUnits(Source unitSource) {
     // Check every library.
     List<CompilationUnit> units = <CompilationUnit>[];
     List<Source> containingLibraries = getLibrariesContaining(unitSource);
     for (Source librarySource in containingLibraries) {
       LibrarySpecificUnit target =
           new LibrarySpecificUnit(librarySource, unitSource);
@@ skipping 1331 matching lines @@
         new PendingFuture<T>(_context, target, computeValue);
     if (!pendingFuture.evaluate(entry)) {
       _context._pendingFutureTargets
           .putIfAbsent(target, () => <PendingFuture>[])
           .add(pendingFuture);
       scheduleComputation();
     }
     return pendingFuture.future;
   }
 }