Convert analysis server over to use ContextBuilder

pkg/analyzer/lib/file_system/memory_file_system.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.file_system.memory_file_system;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:core' hide Resource;
@@ skipping 183 matching lines @@
     path = pathContext.normalize(path);
     newFolder(pathContext.dirname(path));
     _MemoryFile file = new _MemoryFile(this, path);
     _pathToResource[path] = file;
     _pathToBytes[path] = UTF8.encode(content);
     _pathToTimestamp[path] = stamp ?? nextStamp++;
     _notifyWatchers(path, ChangeType.MODIFY);
     return file;
   }
 
+  /**
+   * Write a representation of the file system on the given [sink].
+   */
+  void writeOn(StringSink sink) {
+    List<String> paths = _pathToResource.keys.toList();
+    paths.sort();
+    paths.forEach(sink.writeln);
+  }
+
   void _checkFileAtPath(String path) {
     _MemoryResource resource = _pathToResource[path];
     if (resource is! _MemoryFile) {
       throw new ArgumentError(
           'File expected at "$path" but ${resource.runtimeType} found');
     }
   }
 
   void _checkFolderAtPath(String path) {
     _MemoryResource resource = _pathToResource[path];
@@ skipping 263 matching lines @@
 
   @override
   bool isOrContains(String path) {
     if (path == this.path) {
       return true;
     }
     return contains(path);
   }
 
   @override
+  Folder resolveSymbolicLinksSync() => this;
+
+  @override
   Uri toUri() =>
       new Uri.directory(path, windows: _provider.pathContext == windows);
 }
 
 /**
  * An in-memory implementation of [Resource].
  */
 abstract class _MemoryResource implements Resource {
   final MemoryResourceProvider _provider;
   @override
@@ skipping 36 matching lines @@
   bool operator ==(other) {
     if (runtimeType != other.runtimeType) {
       return false;
     }
     return path == other.path;
   }
 
   @override
   String toString() => path;
 }