Roll Observatory packages and add a roll script

packages/intl/test/message_extraction/failed_extraction_test.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 failed_extraction_test;
+
+import "message_extraction_test.dart";
+import "dart:io";
+import "package:unittest/unittest.dart";
+
+main() {
+  test("Expect warnings but successful extraction", () {
+    runTestWithWarnings(warningsAreErrors: false, expectedExitCode: 0);
+  });
+}
+
+const defaultFiles = const [
+  "sample_with_messages.dart",
+  "part_of_sample_with_messages.dart"
+];
+
+void runTestWithWarnings({bool warningsAreErrors, int expectedExitCode,
+    bool embeddedPlurals: true, List<String> sourceFiles: defaultFiles}) {
+  void verify(ProcessResult result) {
+    try {
+      expect(result.exitCode, expectedExitCode);
+    } finally {
+      deleteGeneratedFiles();
+    }
+  }
+
+  copyFilesToTempDirectory();
+  var program = asTestDirPath("../../bin/extract_to_arb.dart");
+  var args = ["--output-dir=$tempDir"];
+  if (warningsAreErrors) {
+    args.add('--warnings-are-errors');
+  }
+  if (!embeddedPlurals) {
+    args.add('--no-embedded-plurals');
+  }
+  var files = sourceFiles.map(asTempDirPath).toList();
+  var allArgs = [program]
+    ..addAll(args)
+    ..addAll(files);
+  var callback = expectAsync(verify);
+  run(null, allArgs).then(callback);
+}