Issue 27358. Reset AnalysisContext 'sourceFactory' and 'typeSystem' on analysis options change.

pkg/analysis_server/lib/src/context_manager.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 context.directory.manager;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:core';
@@ skipping 867 matching lines @@
         _addSourceFiles(changeSet, child, info);
       }
     }
   }
 
   void _checkForAnalysisOptionsUpdate(
       String path, ContextInfo info, ChangeType changeType) {
     if (AnalysisEngine.isAnalysisOptionsFileName(path, pathContext)) {
       var analysisContext = info.context;
       if (analysisContext is context.AnalysisContextImpl) {
         // TODO(brianwilkerson) This doesn't correctly update the source factory

[Brian Wilkerson, 2016/09/23 13:56:54]

This comment should either be removed or updated.

         // if the changes necessitate it (such as by changing the setting of the
         // strong-mode option).
         Map<String, Object> options = readOptions(info.folder);
         processOptionsForContext(info, options,
             optionsRemoved: changeType == ChangeType.REMOVE);
-        analysisContext.invalidateCachedResults();
+        analysisContext.sourceFactory = _createSourceFactory(
+            analysisContext, analysisContext.analysisOptions, info.folder);
         callbacks.applyChangesToContext(info.folder, new ChangeSet());
       }
     }
   }
 
   void _checkForPackagespecUpdate(
       String path, ContextInfo info, Folder folder) {
     // Check to see if this is the .packages file for this context and if so,
     // update the context's source factory.
     if (absolutePathContext.basename(path) == PACKAGE_SPEC_NAME) {
@@ skipping 912 matching lines @@
     }
     return _embedderLocator;
   }
 
   @override
   SdkExtensionFinder getSdkExtensionFinder(ResourceProvider resourceProvider) {
     return _sdkExtensionFinder ??=
         new SdkExtensionFinder(buildPackageMap(resourceProvider));
   }
 }