src/: Update the remaining include paths of string_split.h to its new location.

ash/test/display_manager_test_api.cc

 // Copyright (c) 2012 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 "ash/test/display_manager_test_api.h"
 
 #include <vector>
 
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
-#include "base/string_split.h"
+#include "base/strings/string_split.h"
 #include "ui/aura/root_window.h"
 #include "ui/gfx/display.h"
 
 namespace ash {
 namespace test {
 typedef std::vector<gfx::Display> DisplayList;
 typedef internal::DisplayInfo DisplayInfo;
 typedef std::vector<DisplayInfo> DisplayInfoList;
 
 namespace {
@@ skipping 61 matching lines @@
 int64 DisplayManagerTestApi::SetFirstDisplayAsInternalDisplay() {
   const gfx::Display& internal = display_manager_->displays_[0];
   gfx::Display::SetInternalDisplayId(internal.id());
   display_manager_->internal_display_info_.reset(new DisplayInfo(
       display_manager_->GetDisplayInfo(internal)));
   return gfx::Display::InternalDisplayId();
 }
 
 }  // namespace test
 }  // namespace ash