When validating cache consistency, skip sources in content cache.

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

 // Copyright (c) 2014, 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.context_test;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 430 matching lines @@
     String path2 = '/test2.dart';
     Source source1 = resourceProvider.newFile(path1, '// 1-1').createSource();
     Source source2 = resourceProvider.newFile(path2, '// 2-1').createSource();
     context.applyChanges(
         new ChangeSet()..addedSource(source1)..addedSource(source2));
     // Same modification times.
     expect(
         validator.sourceModificationTimesComputed([source1, source2],
             [source1.modificationStamp, source2.modificationStamp]),
         isFalse);
+    // Add overlay
+    context.setContents(source1, '// 1-2');
+    expect(
+        validator.sourceModificationTimesComputed([source1, source2],
+            [source1.modificationStamp + 1, source2.modificationStamp]),
+        isFalse);
+    context.setContents(source1, null);
     // Different modification times.
     expect(
         validator.sourceModificationTimesComputed([source1, source2],
             [source1.modificationStamp + 1, source2.modificationStamp]),
         isTrue);
   }
 
   void test_cacheConsistencyValidator_getSources() {
     CacheConsistencyValidator validator = context.cacheConsistencyValidator;
     // Add sources.
     MemoryResourceProvider resourceProvider = new MemoryResourceProvider();
     String path1 = '/test1.dart';
     String path2 = '/test2.dart';
     Source source1 = resourceProvider.newFile(path1, '// 1-1').createSource();
     Source source2 = resourceProvider.newFile(path2, '// 2-1').createSource();
     context.applyChanges(
         new ChangeSet()..addedSource(source1)..addedSource(source2));
-    // No overlays.
-    expect(validator.getSourcesToComputeModificationTimes(),
-        unorderedEquals([source1, source2]));
-    // Add an overlay.
-    context.setContents(source1, '// 1-2');
-    expect(validator.getSourcesToComputeModificationTimes(),
-        unorderedEquals([source2]));
-    // Remove an overlay.
-    context.setContents(source1, null);
+    // Verify.
     expect(validator.getSourcesToComputeModificationTimes(),
         unorderedEquals([source1, source2]));
   }
 
   void test_computeDocumentationComment_class_block() {
     String comment = "/** Comment */";
     Source source = addSource(
         "/test.dart",
         """
 $comment
@@ skipping 3489 matching lines @@
    * Initialize the visitor.
    */
   _ElementGatherer();
 
   @override
   void visitElement(Element element) {
     elements[element] = element;
     super.visitElement(element);
   }
 }