Use a direct include of utf_string_conversions.h in content/.

content/renderer/media/rtc_dtmf_sender_handler.cc

 // Copyright (c) 2013 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/rtc_dtmf_sender_handler.h"
 
 #include <string>
 
 #include "base/logging.h"
-#include "base/utf_string_conversions.h"
+#include "base/strings/utf_string_conversions.h"
 
 using webrtc::DtmfSenderInterface;
 
 namespace content {
 
 RtcDtmfSenderHandler::RtcDtmfSenderHandler(DtmfSenderInterface* dtmf_sender)
     : dtmf_sender_(dtmf_sender),
       webkit_client_(NULL) {
   DVLOG(1) << "::ctor";
   dtmf_sender_->RegisterObserver(this);
@@ skipping 28 matching lines @@
 void RtcDtmfSenderHandler::OnToneChange(const std::string& tone) {
   if (!webkit_client_) {
     LOG(ERROR) << "WebRTCDTMFSenderHandlerClient not set.";
     return;
   }
   webkit_client_->didPlayTone(UTF8ToUTF16(tone));
 }
 
 }  // namespace content