Roll Observatory packages and add a roll script

packages/analyzer/lib/src/generated/incremental_scanner.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 engine.incremental_scanner;
 
 import "dart:math" as math;
 
 import 'package:analyzer/src/generated/engine.dart';
 
@@ skipping 228 matching lines @@
       while (comment != null) {
         comment.offset += delta;
         comment = comment.next;
       }
       token = token.next;
     }
     _tokenMap.put(token, token);
     token.offset += delta;
   }
 }