Share LibrarySpecificUnits when possible

pkg/analyzer/test/src/context/cache_test.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.test.src.context.cache_test;
 
 import 'package:analyzer/src/context/cache.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/sdk_io.dart';
@@ skipping 25 matching lines @@
 
 class AbstractCacheTest {
   InternalAnalysisContext context;
   AnalysisCache cache;
 
   void setUp() {
     context = new _InternalAnalysisContextMock();
     when(context.priorityTargets).thenReturn([]);
     cache = createCache(context: context);
     when(context.analysisCache).thenReturn(cache);
+    when(context.canonicalizeTarget(anyObject)).thenInvoke((target) => target);
   }
 }
 
 @reflectiveTest
 class AnalysisCacheTest extends AbstractCacheTest {
   void test_creation() {
     expect(cache, isNotNull);
   }
 
   test_flush() {
@@ skipping 1130 matching lines @@
   }
 }
 
 class _TestAnalysisTarget implements AnalysisTarget {
   @override
   Source get librarySource => null;
 
   @override
   Source get source => null;
 }