Use callbacks in SessionRestore unit tests

chrome/browser/sessions/session_restore_test_helper.cc

Index: chrome/browser/sessions/session_restore_test_helper.cc
diff --git a/chrome/browser/sessions/session_restore_test_helper.cc b/chrome/browser/sessions/session_restore_test_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..678ea992bb6e20c3e410ded7e8fa700906cc59a2
--- /dev/null
+++ b/chrome/browser/sessions/session_restore_test_helper.cc
@@ -0,0 +1,39 @@
+// 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.
+
+#include "chrome/browser/sessions/session_restore_test_helper.h"
+
+#include "content/public/test/test_utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+SessionRestoreTestHelper::SessionRestoreTestHelper()
+    : restore_notification_seen_(false),
+      loop_is_running_(false),
+      weak_ptr_factory(this) {
+  callback_subscription_ = SessionRestore::RegisterOnSessionRestoredCallback(
+      base::Bind(&SessionRestoreTestHelper::OnSessionRestoreDone,
+                 weak_ptr_factory.GetWeakPtr()));
+}
+
+SessionRestoreTestHelper::~SessionRestoreTestHelper() {
+}
+
+void SessionRestoreTestHelper::Wait() {
+  if (restore_notification_seen_)
+    return;
+
+  loop_is_running_ = true;
+  message_loop_runner_ = new content::MessageLoopRunner;
+  message_loop_runner_->Run();
+  EXPECT_TRUE(restore_notification_seen_);
+}
+
+void SessionRestoreTestHelper::OnSessionRestoreDone() {
+  restore_notification_seen_ = true;
+  if (!loop_is_running_)
+    return;
+
+  message_loop_runner_->Quit();
+  loop_is_running_ = false;
+}