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

content/browser/download/download_request_handle.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_request_handle.h"
 
 #include "base/bind.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 DownloadRequestHandle::~DownloadRequestHandle() {
 }
 
@@ skipping 61 matching lines @@
                             " child_id = %d"
                             " render_view_id = %d"
                             " request_id = %d"
                             "}",
                             child_id_,
                             render_view_id_,
                             request_id_);
 }
 
 }  // namespace content