Remove "top_down" flag in the message center code

ui/message_center/views/message_center_view_unittest.cc

 // Copyright 2013 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 "ui/message_center/views/message_center_view.h"
 
 #include <map>
 #include <memory>
 #include <utility>
 
@@ skipping 197 matching lines @@
       message_center::RichNotificationData(), nullptr);
 
   // ...and a list for it.
   notifications_[std::string(kNotificationId1)] = std::move(notification1);
   notifications_[std::string(kNotificationId2)] = std::move(notification2);
   NotificationList::Notifications notifications = Notifications();
   message_center_->SetVisibleNotifications(notifications);
 
   // Then create a new MessageCenterView with that single notification.
   message_center_view_.reset(new MessageCenterView(
-      message_center_.get(), NULL, 100, false, /*top_down =*/false));
+      message_center_.get(), NULL, 100, false));
   GetMessageListView()->quit_message_loop_after_animation_for_test_ = true;
   GetMessageCenterView()->SetBounds(0, 0, 380, 600);
   message_center_view_->SetNotifications(notifications);
   message_center_view_->set_owned_by_client();
 
   widget_.reset(new views::Widget());
   views::Widget::InitParams params =
       CreateParams(views::Widget::InitParams::TYPE_POPUP);
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.bounds = gfx::Rect(50, 50, 650, 650);
@@ skipping 590 matching lines @@
       base::UTF8ToUTF16("title1"), base::UTF8ToUTF16("message"), gfx::Image(),
       base::UTF8ToUTF16("display source"), GURL(),
       NotifierId(NotifierId::APPLICATION, "extension_id"),
       message_center::RichNotificationData(), nullptr));
 
   GetMessageCenterView()->SizeToPreferredSize();
   EXPECT_NE(kEmptyMessageCenterViewHeight, GetMessageCenterView()->height());
 }
 
 }  // namespace message_center