Preparational work for an upcoming addition of a threadchecking scheme for APM

webrtc/modules/audio_processing/echo_cancellation_impl.cc

Index: webrtc/modules/audio_processing/echo_cancellation_impl.cc
diff --git a/webrtc/modules/audio_processing/echo_cancellation_impl.cc b/webrtc/modules/audio_processing/echo_cancellation_impl.cc
index e1e093f9cc3aeddbc3ee0ddfecdc687a1b2d654a..96879c4cd5423e43e6ff5a09c027c67e66e8d4a3 100644
--- a/webrtc/modules/audio_processing/echo_cancellation_impl.cc
+++ b/webrtc/modules/audio_processing/echo_cancellation_impl.cc
@@ -58,11 +58,14 @@ AudioProcessing::Error MapError(int err) {
 const size_t EchoCancellationImpl::kAllowedValuesOfSamplesPerFrame1;
 const size_t EchoCancellationImpl::kAllowedValuesOfSamplesPerFrame2;
 
-EchoCancellationImpl::EchoCancellationImpl(const AudioProcessing* apm,
-                                           CriticalSectionWrapper* crit)
+EchoCancellationImpl::EchoCancellationImpl(
+    const AudioProcessing* apm,
+    CriticalSectionWrapper* crit,
+    const rtc::ThreadChecker* render_thread_checker)
     : ProcessingComponent(),
       apm_(apm),
       crit_(crit),
+      render_thread_checker_(render_thread_checker),
       drift_compensation_enabled_(false),
       metrics_enabled_(false),
       suppression_level_(kModerateSuppression),
@@ -79,6 +82,7 @@ EchoCancellationImpl::EchoCancellationImpl(const AudioProcessing* apm,
 EchoCancellationImpl::~EchoCancellationImpl() {}
 
 int EchoCancellationImpl::ProcessRenderAudio(const AudioBuffer* audio) {
+  RTC_DCHECK(render_thread_checker_->CalledOnValidThread());
   if (!is_component_enabled()) {
     return apm_->kNoError;
   }
@@ -438,7 +442,6 @@ int EchoCancellationImpl::ConfigureHandle(void* handle) const {
   config.nlpMode = MapSetting(suppression_level_);
   config.skewMode = drift_compensation_enabled_;
   config.delay_logging = delay_logging_enabled_;
-
   WebRtcAec_enable_extended_filter(
       WebRtcAec_aec_core(static_cast<Handle*>(handle)),
       extended_filter_enabled_ ? 1 : 0);