Use a direct include of strings headers in url/, win8/.

url/url_canon.h

 // 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.
 
 #ifndef URL_URL_CANON_H_
 #define URL_URL_CANON_H_
 
 #include <stdlib.h>
 #include <string.h>
 
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "url/url_export.h"
 #include "url/url_parse.h"
 
 namespace url_canon {
 
 // Canonicalizer output -------------------------------------------------------
 
 // Base class for the canonicalizer output, this maintains a buffer and
 // supports simple resizing and append operations on it.
 //
@@ skipping 861 matching lines @@
     bool base_is_file,
     const char16* relative_url,
     const url_parse::Component& relative_component,
     CharsetConverter* query_converter,
     CanonOutput* output,
     url_parse::Parsed* out_parsed);
 
 }  // namespace url_canon
 
 #endif  // URL_URL_CANON_H_