Use a direct include of strings headers in ui/, part 2.

ui/message_center/message_center_impl_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/message_center_impl.h"
 
 #include "base/bind.h"
 #include "base/message_loop.h"
 #include "base/run_loop.h"
-#include "base/utf_string_conversions.h"
+#include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/notification_types.h"
 
 namespace message_center {
 namespace {
 
 class MessageCenterImplTest : public testing::Test,
                               public MessageCenterObserver {
  public:
@@ skipping 180 matching lines @@
 
   run_loop()->Run();
 
   EXPECT_EQ(popup_timers_controller->last_id(), "test");
   EXPECT_TRUE(popup_timers_controller->timer_finished());
 }
 
 }  // namespace internal
 
 }  // namespace message_center