Stop running pub get at gclient sync time and fix build bugs

mojo/public/dart/third_party/test/lib/src/frontend/future_matchers.dart

+// Copyright (c) 2012, 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 test.frontend.future_matchers;
+
+import 'dart:async';
+
+import 'package:matcher/matcher.dart' hide throws, throwsA, expect, fail;
+
+import '../backend/invoker.dart';
+import 'expect.dart';
+
+/// Matches a [Future] that completes successfully with a value.
+///
+/// Note that this creates an asynchronous expectation. The call to `expect()`
+/// that includes this will return immediately and execution will continue.
+/// Later, when the future completes, the actual expectation will run.
+///
+/// To test that a Future completes with an exception, you can use [throws] and
+/// [throwsA].
+final Matcher completes = const _Completes(null);
+
+/// Matches a [Future] that completes succesfully with a value that matches
+/// [matcher].
+///
+/// Note that this creates an asynchronous expectation. The call to
+/// `expect()` that includes this will return immediately and execution will
+/// continue. Later, when the future completes, the actual expectation will run.
+///
+/// To test that a Future completes with an exception, you can use [throws] and
+/// [throwsA].
+///
+/// The [description] parameter is deprecated and shouldn't be used.
+Matcher completion(matcher, [@deprecated String description]) =>
+    new _Completes(wrapMatcher(matcher));
+
+class _Completes extends Matcher {
+  final Matcher _matcher;
+
+  const _Completes(this._matcher);
+
+  bool matches(item, Map matchState) {
+    if (item is! Future) return false;
+    Invoker.current.addOutstandingCallback();
+
+    item.then((value) {
+      if (_matcher != null) expect(value, _matcher);
+      Invoker.current.removeOutstandingCallback();
+    });
+
+    return true;
+  }
+
+  Description describe(Description description) {
+    if (_matcher == null) {
+      description.add('completes successfully');
+    } else {
+      description.add('completes to a value that ').addDescriptionOf(_matcher);
+    }
+    return description;
+  }
+}