Use a direct include of the message_loop header in ui/, part 2.

ui/message_center/views/message_popup_collection_unittest.cc

 // Copyright (c) 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_popup_collection.h"
 
 #include <list>
 
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/rect.h"
 #include "ui/message_center/fake_message_center.h"
 #include "ui/message_center/views/toast_contents_view.h"
 #include "ui/views/test/views_test_base.h"
 #include "ui/views/widget/widget.h"
 
 namespace message_center {
@@ skipping 154 matching lines @@
 
   CloseAllToastsAndWait();
   EXPECT_EQ(0u, GetToastCounts());
 }
 
 // TODO(dimich): Test repositioning - both normal one and when user is closing
 // the toasts.
 
 }  // namespace test
 }  // namespace message_center