chrome: Update include paths of string_split.h to its new location.

chrome/common/extensions/csp_validator.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/extensions/csp_validator.h"
 
-#include "base/string_split.h"
 #include "base/string_util.h"
+#include "base/strings/string_split.h"
 #include "base/strings/string_tokenizer.h"
 
 namespace extensions {
 
 namespace csp_validator {
 
 namespace {
 
 const char kDefaultSrc[] = "default-src";
 const char kScriptSrc[] = "script-src";
@@ skipping 173 matching lines @@
       }
     }
   }
 
   return seen_sandbox;
 }
 
 }  // csp_validator
 
 }  // extensions