Add multi-process notification class.

chrome/common/multi_process_notification.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/common/multi_process_notification.h"
+
+#include "base/task.h"
+
+namespace multi_process_notification {
+
+PerformTaskOnNotification::PerformTaskOnNotification(Task* task) : task_(task) {
+}
+
+PerformTaskOnNotification::~PerformTaskOnNotification() {
+}
+
+void PerformTaskOnNotification::OnNotificationReceived(
+    const std::string& name, Domain domain) {
+  task_->Run();
+  task_.reset();
+}
+
+bool PerformTaskOnNotification::WasNotificationReceived() {
+  return task_.get() == NULL;
+}
+
+}  // namespace multi_process_notification