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

chrome/common/chrome_content_client_unittest.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/chrome_content_client.h"
 
 #include "base/command_line.h"
-#include "base/string_split.h"
+#include "base/strings/string_split.h"
 #include "content/public/common/content_switches.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 void CheckUserAgentStringOrdering(bool mobile_device) {
   std::vector<std::string> pieces;
 
   // Check if the pieces of the user agent string come in the correct order.
   chrome::ChromeContentClient content_client;
@@ skipping 56 matching lines @@
   CheckUserAgentStringOrdering(false);
 
   // Do it for mobile devices.
   command_line->AppendSwitch(switches::kUseMobileUserAgent);
   ASSERT_TRUE(command_line->HasSwitch(switches::kUseMobileUserAgent));
   CheckUserAgentStringOrdering(true);
 #endif
 }
 
 }  // namespace chrome_common