Use a direct include of strings headers in content/renderer and content/shell.

content/renderer/media/mock_media_stream_dispatcher.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/renderer/media/mock_media_stream_dispatcher.h"
 
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "content/public/common/media_stream_request.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace content {
 
 MockMediaStreamDispatcher::MockMediaStreamDispatcher()
     : MediaStreamDispatcher(NULL),
       request_id_(-1),
       request_stream_counter_(0),
       stop_stream_counter_(0) {
@@ skipping 47 matching lines @@
                                                 int index) {
   return -1;
 }
 
 int MockMediaStreamDispatcher::audio_session_id(const std::string& label,
                                                 int index) {
   return -1;
 }
 
 }  // namespace content