src/: Update the remaining include paths of string_split.h to its new location.

net/base/mime_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 <algorithm>
 #include <iterator>
 #include <map>
 #include <string>
 
 #include "net/base/mime_util.h"
 #include "net/base/platform_mime_util.h"
 
 #include "base/hash_tables.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
-#include "base/string_split.h"
 #include "base/string_util.h"
+#include "base/strings/string_split.h"
 #include "base/utf_string_conversions.h"
 
 using std::string;
 
 namespace {
 
 struct MediaType {
   const char name[12];
   const char matcher[13];
 };
@@ skipping 951 matching lines @@
   return CERTIFICATE_MIME_TYPE_UNKNOWN;
 }
 
 bool IsSupportedCertificateMimeType(const std::string& mime_type) {
   CertificateMimeType file_type =
       GetCertificateMimeTypeForMimeType(mime_type);
   return file_type != CERTIFICATE_MIME_TYPE_UNKNOWN;
 }
 
 }  // namespace net