Roll Observatory packages and add a roll script

packages/analyzer/example/resolver_driver.dart

+#!/usr/bin/env dart
+// Copyright (c) 2013, 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.
+
+import 'dart:io';
+
+import 'package:analyzer/src/generated/ast.dart';
+import 'package:analyzer/src/generated/element.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/java_io.dart';
+import 'package:analyzer/src/generated/sdk.dart' show DartSdk;
+import 'package:analyzer/src/generated/sdk_io.dart' show DirectoryBasedDartSdk;
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/generated/source_io.dart';
+
+void main(List<String> args) {
+  print('working dir ${new File('.').resolveSymbolicLinksSync()}');
+
+  if (args.length < 2 || args.length > 3) {
+    print(_usage);
+    exit(0);
+  }
+
+  String packageRoot;
+  if (args.length == 3) {
+    packageRoot = args[2];
+  }
+
+  JavaSystemIO.setProperty("com.google.dart.sdk", args[0]);
+  DartSdk sdk = DirectoryBasedDartSdk.defaultSdk;
+
+  var resolvers = [new DartUriResolver(sdk), new FileUriResolver()];
+
+  if (packageRoot != null) {
+    var packageDirectory = new JavaFile(packageRoot);
+    resolvers.add(new PackageUriResolver([packageDirectory]));
+  }
+
+  AnalysisContext context = AnalysisEngine.instance.createAnalysisContext()
+    ..sourceFactory = new SourceFactory(resolvers);
+
+  Source source = new FileBasedSource(new JavaFile(args[1]));
+  ChangeSet changeSet = new ChangeSet()..addedSource(source);
+  context.applyChanges(changeSet);
+  LibraryElement libElement = context.computeLibraryElement(source);
+  print("libElement: $libElement");
+
+  CompilationUnit resolvedUnit =
+      context.resolveCompilationUnit(source, libElement);
+  var visitor = new _ASTVisitor();
+  resolvedUnit.accept(visitor);
+}
+
+const _usage =
+    'Usage: resolve_driver <path_to_sdk> <file_to_resolve> [<packages_root>]';
+
+class _ASTVisitor extends GeneralizingAstVisitor {
+  visitNode(AstNode node) {
+    var lines = <String>['${node.runtimeType} : <"$node">'];
+    if (node is SimpleIdentifier) {
+      Element element = node.staticElement;
+      if (element != null) {
+        lines.add('  element: ${element.runtimeType}');
+        LibraryElement library = element.library;
+        if (library != null) {
+          var fullName =
+              element.library.definingCompilationUnit.source.fullName;
+          lines.add("  from $fullName");
+        }
+      }
+    }
+    print(lines.join('\n'));
+    return super.visitNode(node);
+  }
+}