Roll Observatory packages and add a roll script

packages/charted/tool/hop_runner.dart

+//
+// Copyright 2014 Google Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+//
+
+library charted.tool.hop_runner;
+
+import 'package:hop/hop.dart';
+import 'dart:io';
+
+main(List<String> args) {
+  addTask('unit-test', createUnitTestsTask());
+  runHop(args);
+}
+
+Task createUnitTestsTask() =>
+  new Task((TaskContext context) {
+    context.info("Running tests...");
+    return Process.run('./content_shell',
+        ['--dump-render-tree','test/test_in_browser.html']).
+            then((ProcessResult process) =>
+                checkTestsOutput(context, process));
+  });
+
+/// Reads the output from content_shell and checks for number of tests
+/// passed/failed/erred. This method requires that the tests be done
+/// in simple html unit test configuration - useHtmlConfiguration().
+void checkTestsOutput(TaskContext context, ProcessResult process) {
+  var output = (process.stdout as String),
+      failRegEx = new RegExp(r"^[0-9]+\s+FAIL\s"),
+      errorRegEx = new RegExp(r"^[0-9]+\s+ERROR\s"),
+      failCount = 0,
+      errorCount = 0;
+
+  context.info(output);
+
+  for (var line in output.split('\n')) {
+    if (line.contains(failRegEx)) failCount++;
+    if (line.contains(errorRegEx)) errorCount++;
+  }
+
+  if (failCount + errorCount > 0) {
+    context.fail('FAIL: $failCount\nERROR: $errorCount');
+  }
+}