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

chrome/browser/ui/app_list/search/mixer_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 <string>
 
 #include "base/memory/scoped_vector.h"
-#include "base/string16.h"
-#include "base/stringprintf.h"
+#include "base/strings/string16.h"
+#include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/app_list/search/chrome_search_result.h"
 #include "chrome/browser/ui/app_list/search/history_types.h"
 #include "chrome/browser/ui/app_list/search/mixer.h"
 #include "chrome/browser/ui/app_list/search/search_provider.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/app_list/app_list_model.h"
 
 namespace app_list {
 namespace test {
@@ skipping 153 matching lines @@
   webstore_provider()->set_count(1);
 
   RunQuery();
 
   // Only three results with unique id are kept.
   EXPECT_EQ("dup0,dup1,dup2", GetResults());
 }
 
 }  // namespace test
 }  // namespace app_list