Adding ThreadChecker validation to d'tors for protocol classes

remoting/protocol/audio_decode_scheduler.cc

Index: remoting/protocol/audio_decode_scheduler.cc
diff --git a/remoting/protocol/audio_decode_scheduler.cc b/remoting/protocol/audio_decode_scheduler.cc
index f251e5be329d03c7a6c99c21cc76fe50785fd672..996453866a522aa7ba59e6189ee4e1d07798a151 100644
--- a/remoting/protocol/audio_decode_scheduler.cc
+++ b/remoting/protocol/audio_decode_scheduler.cc
@@ -25,6 +25,7 @@ AudioDecodeScheduler::AudioDecodeScheduler(
       weak_factory_(this) {}
 
 AudioDecodeScheduler::~AudioDecodeScheduler() {
+  DCHECK(thread_checker_.CalledOnValidThread());
   audio_decode_task_runner_->DeleteSoon(FROM_HERE, decoder_.release());
 }