Use a direct include of strings headers in content/browser/, part 1.

content/browser/download/download_stats.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 "content/browser/download/download_stats.h"
 
 #include "base/metrics/histogram.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "content/browser/download/download_resource_handler.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "net/http/http_content_disposition.h"
 
 namespace content {
 
 namespace {
 
 // All possible error codes from the network module. Note that the error codes
 // are all positive (since histograms expect positive sample values).
@@ skipping 431 matching lines @@
                            disk_write_time_ms * 100 / elapsed_time_ms);
 }
 
 void RecordSavePackageEvent(SavePackageEvent event) {
   UMA_HISTOGRAM_ENUMERATION("Download.SavePackage",
                             event,
                             SAVE_PACKAGE_LAST_ENTRY);
 }
 
 }  // namespace content