Use a direct include of strings headers in ui/, part 3.

ui/gfx/font_list_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/gfx/font_list.h"
 
 #include <string>
 #include <vector>
 
-#include "base/string_number_conversions.h"
+#include "base/strings/string_number_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 // Helper function for comparing fonts for equality.
 std::string FontToString(const gfx::Font& font) {
   std::string font_string = font.GetFontName();
   font_string += "|";
   font_string += base::IntToString(font.GetFontSize());
   int style = font.GetStyle();
@@ skipping 205 matching lines @@
 
   FontList derived = font_list.DeriveFontListWithSize(5);
   const std::vector<Font>& derived_fonts = derived.GetFonts();
 
   EXPECT_EQ(2U, derived_fonts.size());
   EXPECT_EQ("Arial|5", FontToString(derived_fonts[0]));
   EXPECT_EQ("Sans serif|5", FontToString(derived_fonts[1]));
 }
 
 }  // namespace gfx