Reuse CompilationUnitElement in BuildCompilationUnitElementTask.

pkg/analyzer/test/src/context/abstract_context.dart

Index: pkg/analyzer/test/src/context/abstract_context.dart
diff --git a/pkg/analyzer/test/src/context/abstract_context.dart b/pkg/analyzer/test/src/context/abstract_context.dart
index 918e02578d89f3a0f5d7b0949f64bddccb0fa146..a4a374fb7ecf3e546acdebaa501cd6daaf8a4d53 100644
--- a/pkg/analyzer/test/src/context/abstract_context.dart
+++ b/pkg/analyzer/test/src/context/abstract_context.dart
@@ -6,10 +6,11 @@ library test.src.task.abstract_context_test;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
+import 'package:analyzer/src/context/cache.dart';
 import 'package:analyzer/src/context/context.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart'
-    hide AnalysisContextImpl, AnalysisTask;
+    hide AnalysisCache, AnalysisContextImpl, AnalysisTask;
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/driver.dart';
@@ -23,6 +24,7 @@ class AbstractContextTest {
   DartSdk sdk = new MockSdk();
   SourceFactory sourceFactory;
   AnalysisContextImpl context;
+  AnalysisCache analysisCache;
   AnalysisDriver analysisDriver;
 
   Source addSource(String path, String contents) {
@@ -88,6 +90,7 @@ class AbstractContextTest {
     ]);
     context = createAnalysisContext();
     context.sourceFactory = sourceFactory;
+    analysisCache = context.analysisCache;
     analysisDriver = context.driver;
   }