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

ui/base/models/list_selection_model_unittest.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 "ui/base/models/list_selection_model.h"
 
 #include <algorithm>
 #include <string>
 
-#include "base/string_number_conversions.h"
+#include "base/strings/string_number_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace ui {
 
 typedef testing::Test ListSelectionModelTest;
 
 // Returns the state of the selection model as a string. The format is:
 // 'active=X anchor=X selection=X X X...'.
 static std::string StateAsString(const ListSelectionModel& model) {
   std::string result = "active=" + base::IntToString(model.active()) +
@@ skipping 167 matching lines @@
 
   EXPECT_TRUE(model1.Equals(model2));
   EXPECT_TRUE(model2.Equals(model1));
 
   model2.SetSelectedIndex(0);
   EXPECT_FALSE(model1.Equals(model2));
   EXPECT_FALSE(model2.Equals(model1));
 }
 
 }  // namespace ui