Use explicit WebString <-> string16 conversion methods in media files

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/bind.h"
 #include "base/location.h"
@@ skipping 51 matching lines @@
   // Release |observer| before |weak_factory_| is destroyed.
   observer_ = NULL;
 }
 
 void RtcDtmfSenderHandler::setClient(
     blink::WebRTCDTMFSenderHandlerClient* client) {
   webkit_client_ = client;
 }
 
 blink::WebString RtcDtmfSenderHandler::currentToneBuffer() {
-  return base::UTF8ToUTF16(dtmf_sender_->tones());
+  return blink::WebString::fromUTF8(dtmf_sender_->tones());
 }
 
 bool RtcDtmfSenderHandler::canInsertDTMF() {
   return dtmf_sender_->CanInsertDtmf();
 }
 
 bool RtcDtmfSenderHandler::insertDTMF(const blink::WebString& tones,
                                       long duration,
                                       long interToneGap) {
-  std::string utf8_tones = base::UTF16ToUTF8(base::StringPiece16(tones));
+  std::string utf8_tones = tones.utf8();
   return dtmf_sender_->InsertDtmf(utf8_tones, static_cast<int>(duration),
                                   static_cast<int>(interToneGap));
 }
 
 void RtcDtmfSenderHandler::OnToneChange(const std::string& tone) {
   if (!webkit_client_) {
     LOG(ERROR) << "WebRTCDTMFSenderHandlerClient not set.";
     return;
   }
-  webkit_client_->didPlayTone(base::UTF8ToUTF16(tone));
+  webkit_client_->didPlayTone(blink::WebString::fromUTF8(tone));
 }
 
 }  // namespace content
-