Move DTMF sender to RtpSender (as opposed to WebRtcSession).

webrtc/pc/dtmfsender.h

 /*
  *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 16 matching lines @@
 namespace rtc {
 class Thread;
 }
 
 namespace webrtc {
 
 // This interface is called by DtmfSender to talk to the actual audio channel
 // to send DTMF.
 class DtmfProviderInterface {
  public:
-  // Returns true if the audio track with given id (|track_id|) is capable
-  // of sending DTMF. Otherwise returns false.
-  virtual bool CanInsertDtmf(const std::string& track_id) = 0;
-  // Sends DTMF |code| via the audio track with given id (|track_id|).
+  // Returns true if the audio sender is capable of sending DTMF. Otherwise
+  // returns false.
+  virtual bool CanInsertDtmf() = 0;
+  // Sends DTMF |code|.
   // The |duration| indicates the length of the DTMF tone in ms.
   // Returns true on success and false on failure.
-  virtual bool InsertDtmf(const std::string& track_id,
-                          int code, int duration) = 0;
+  virtual bool InsertDtmf(int code, int duration) = 0;
   // Returns a |sigslot::signal0<>| signal. The signal should fire before
   // the provider is destroyed.
   virtual sigslot::signal0<>* GetOnDestroyedSignal() = 0;
 
  protected:
   virtual ~DtmfProviderInterface() {}
 };
 
 class DtmfSender
     : public DtmfSenderInterface,
       public sigslot::has_slots<>,
       public rtc::MessageHandler {
  public:
+  // |track| is only there for backwards compatibility, since there's a track
+  // accessor method.
   static rtc::scoped_refptr<DtmfSender> Create(
       AudioTrackInterface* track,
       rtc::Thread* signaling_thread,
       DtmfProviderInterface* provider);
 
   // Implements DtmfSenderInterface.
   void RegisterObserver(DtmfSenderObserverInterface* observer) override;
   void UnregisterObserver() override;
   bool CanInsertDtmf() override;
   bool InsertDtmf(const std::string& tones,
@@ skipping 46 matching lines @@
   PROXY_CONSTMETHOD0(int, duration)
   PROXY_CONSTMETHOD0(int, inter_tone_gap)
 END_PROXY_MAP()
 
 // Get DTMF code from the DTMF event character.
 bool GetDtmfCode(char tone, int* code);
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_PC_DTMFSENDER_H_