Roll Observatory packages and add a roll script

packages/smoke/test/codegen/common.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 smoke.test.codegen.common;
+
+import 'package:smoke/codegen/generator.dart';
+import 'package:unittest/unittest.dart';
+
+checkResults(SmokeCodeGenerator generator,
+    {List<String> imports: const [], String topLevel: '', String initCall}) {
+  var allImports = []
+    ..addAll(DEFAULT_IMPORTS)
+    ..addAll(imports)
+    ..add('');
+  var genImports = new StringBuffer();
+  generator.writeImports(genImports);
+  expect(genImports.toString(), allImports.join('\n'));
+
+  var genTopLevel = new StringBuffer();
+  generator.writeTopLevelDeclarations(genTopLevel);
+  expect(genTopLevel.toString(), topLevel);
+
+  var indentedCode = initCall.replaceAll("\n", "\n  ").trim();
+  var genInitCall = new StringBuffer();
+  genInitCall.write('  useGeneratedCode(');
+  generator.writeStaticConfiguration(genInitCall);
+  genInitCall.writeln(');');
+  expect(genInitCall.toString(), '  $indentedCode\n');
+}