Use a direct include of strings headers in chrome/test/.

chrome/test/webdriver/webdriver_dispatch_unittest.cc

 // Copyright (c) 2011 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 "base/format_macros.h"
 #include "base/json/json_reader.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "chrome/test/webdriver/commands/response.h"
 #include "chrome/test/webdriver/http_response.h"
 #include "chrome/test/webdriver/webdriver_dispatch.h"
 #include "chrome/test/webdriver/webdriver_session_manager.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/mongoose/mongoose.h"
 
 namespace webdriver {
 
@@ skipping 194 matching lines @@
       &parameters,
       &response));
   EXPECT_EQ("GET", method);
   ASSERT_EQ(3u, path_segments.size());
   EXPECT_EQ("", path_segments[0]);
   EXPECT_EQ("bar", path_segments[1]);
   EXPECT_EQ("baz", path_segments[2]);
 }
 
 }  // namespace webdriver