Use a direct include of strings headers in chrome/common/, part 1.

chrome/common/custom_handlers/protocol_handler.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/common/custom_handlers/protocol_handler.h"
 
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "net/base/escape.h"
 
 
 ProtocolHandler::ProtocolHandler(const std::string& protocol,
                                  const GURL& url,
                                  const string16& title)
     : protocol_(protocol),
       url_(url),
       title_(title) {
@@ skipping 68 matching lines @@
     title_ == other.title_;
 }
 
 bool ProtocolHandler::IsEquivalent(const ProtocolHandler& other) const {
   return protocol_ == other.protocol_ && url_ == other.url_;
 }
 
 bool ProtocolHandler::operator<(const ProtocolHandler& other) const {
   return title_ < other.title_;
 }