Making WebRtcSession fire a destroyed signal.

talk/app/webrtc/dtmfsender.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 81 matching lines @@
                        rtc::Thread* signaling_thread,
                        DtmfProviderInterface* provider)
     : track_(track),
       observer_(NULL),
       signaling_thread_(signaling_thread),
       provider_(provider),
       duration_(kDtmfDefaultDurationMs),
       inter_tone_gap_(kDtmfDefaultGapMs) {
   ASSERT(track_ != NULL);
   ASSERT(signaling_thread_ != NULL);
+  // TODO(deadbeef): Once we can use shared_ptr and weak_ptr,
+  // do that instead of relying on a "destroyed" signal.
   if (provider_) {
     ASSERT(provider_->GetOnDestroyedSignal() != NULL);
     provider_->GetOnDestroyedSignal()->connect(
         this, &DtmfSender::OnProviderDestroyed);
   }
 }
 
 DtmfSender::~DtmfSender() {
-  if (provider_) {
-    ASSERT(provider_->GetOnDestroyedSignal() != NULL);
-    provider_->GetOnDestroyedSignal()->disconnect(this);

[Taylor Brandstetter, 2016/01/16 00:55:10]

This doesn't hurt anything, but it's pointless since ~sigslot::has_slots()
already takes care of disconnecting signals.

-  }
   StopSending();
 }
 
 void DtmfSender::RegisterObserver(DtmfSenderObserverInterface* observer) {
   observer_ = observer;
 }
 
 void DtmfSender::UnregisterObserver() {
   observer_ = NULL;
 }
@@ skipping 124 matching lines @@
   LOG(LS_INFO) << "The Dtmf provider is deleted. Clear the sending queue.";
   StopSending();
   provider_ = NULL;
 }
 
 void DtmfSender::StopSending() {
   signaling_thread_->Clear(this);
 }
 
 }  // namespace webrtc