Roll Observatory packages and add a roll script

packages/analyzer/lib/src/task/incremental_element_builder.dart

 // Copyright (c) 2015, 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.src.task.incremental_element_builder;
 
 import 'dart:collection';
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
@@ skipping 51 matching lines @@
 
   /**
    * Updates [oldUnit] to have the same directives and declarations, in the
    * same order as in [newUnit]. Existing resolution is kept where possible.
    *
    * Updates [unitElement] by adding/removing elements as needed.
    *
    * Fills [unitDelta] with added/remove elements.
    */
   void build() {
-    new CompilationUnitBuilder().buildCompilationUnit(
-        unitSource, newUnit, librarySource);
+    new CompilationUnitBuilder()
+        .buildCompilationUnit(unitSource, newUnit, librarySource);
     _processDirectives();
     _processUnitMembers();
     newUnit.element = unitElement;
     _replaceUnitContents(oldUnit, newUnit);
   }
 
   void _addElementToHolder(Element element) {
     if (element is PropertyAccessorElement) {
       holder.addAccessor(element);
     } else if (element is ClassElement) {
@@ skipping 273 matching lines @@
     }
     int oldOffset = element.nameOffset;
     int newOffset = map[oldOffset];
     assert(newOffset != null);
     (element as ElementImpl).nameOffset = newOffset;
     if (element is! LibraryElement) {
       super.visitElement(element);
     }
   }
 }