Adding ThreadChecker validation to d'tors for protocol classes

remoting/protocol/webrtc_audio_source_adapter.cc

Index: remoting/protocol/webrtc_audio_source_adapter.cc
diff --git a/remoting/protocol/webrtc_audio_source_adapter.cc b/remoting/protocol/webrtc_audio_source_adapter.cc
index cd281494150a729050c23eaa42096443e183daf4..fc6d8943d31a6cbde64fa506f527d31d9d9d4a27 100644
--- a/remoting/protocol/webrtc_audio_source_adapter.cc
+++ b/remoting/protocol/webrtc_audio_source_adapter.cc
@@ -59,7 +59,9 @@ WebrtcAudioSourceAdapter::Core::Core() {
   thread_checker_.DetachFromThread();
 }
 
-WebrtcAudioSourceAdapter::Core::~Core() {}
+WebrtcAudioSourceAdapter::Core::~Core() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
 
 void WebrtcAudioSourceAdapter::Core::Start(
     std::unique_ptr<AudioSource> audio_source) {