Use callbacks in SessionRestore unit tests

chrome/browser/sessions/session_restore_test_helper.h

+// Copyright 2015 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.
+
+#ifndef CHROME_BROWSER_SESSIONS_SESSION_RESTORE_TEST_HELPER_H_
+#define CHROME_BROWSER_SESSIONS_SESSION_RESTORE_TEST_HELPER_H_
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/sessions/session_restore.h"
+
+namespace content {
+class MessageLoopRunner;
+}
+
+// This class waits on the SessionRestore notification. It is a replacement for
+// content::WindowedNotificationObserver, which uses notification service. This
+// class uses the callback-based notification instead.
+class SessionRestoreTestHelper {
+ public:
+  SessionRestoreTestHelper();
+  ~SessionRestoreTestHelper();
+
+  // Blocks until OnSessionRestore() is called.
+  void Wait();
+
+ private:
+  // Callback for session restore notifications.
+  void OnSessionRestoreDone();
+
+  // Indicates whether a session restore notification has been received.
+  bool restore_notification_seen_;
+
+  // Indicates whether |message_loop_runner_| is running.
+  bool loop_is_running_;
+
+  // Loop that runs while waiting for notification callback.
+  scoped_refptr<content::MessageLoopRunner> message_loop_runner_;
+
+  // For automatically unsubscribing from callback-based notifications.
+  SessionRestore::CallbackSubscription callback_subscription_;
+
+  // For safely binding pointers to callbacks.
+  base::WeakPtrFactory<SessionRestoreTestHelper> weak_ptr_factory;
+
+  DISALLOW_COPY_AND_ASSIGN(SessionRestoreTestHelper);
+};
+
+#endif  // CHROME_BROWSER_SESSIONS_SESSION_RESTORE_TEST_HELPER_H_