Use a direct include of strings headers in chrome/browser/chromeos/.

chrome/browser/chromeos/contacts/contact_test_util.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 "chrome/browser/chromeos/contacts/contact_test_util.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
-#include "base/string_util.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
 #include "base/time.h"
 #include "chrome/browser/chromeos/contacts/contact_map.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "ui/gfx/codec/png_codec.h"
 #include "ui/gfx/size.h"
 
 namespace contacts {
 namespace test {
 
@@ skipping 222 matching lines @@
   SkCanvas canvas(bitmap);
   canvas.clear(SK_ColorBLACK);
 
   std::vector<unsigned char> png_photo;
   CHECK(gfx::PNGCodec::EncodeBGRASkBitmap(bitmap, false, &png_photo));
   contact->set_raw_untrusted_photo(&png_photo[0], png_photo.size());
 }
 
 }  // namespace test
 }  // namespace contacts