Refactoring of the buffering of the nearend signal done inside the AEC

webrtc/modules/audio_processing/aec/echo_cancellation.cc

Index: webrtc/modules/audio_processing/aec/echo_cancellation.cc
diff --git a/webrtc/modules/audio_processing/aec/echo_cancellation.cc b/webrtc/modules/audio_processing/aec/echo_cancellation.cc
index c26b1a0fd89102249a4d2d7581453bdee75a7834..4f65c2b9830717696e51c430467d4a5b392ed029 100644
--- a/webrtc/modules/audio_processing/aec/echo_cancellation.cc
+++ b/webrtc/modules/audio_processing/aec/echo_cancellation.cc
@@ -683,6 +683,7 @@ static void ProcessExtended(Aec* self,
                             int32_t skew) {
   size_t i;
   const int delay_diff_offset = kDelayDiffOffsetSamples;
+  RTC_DCHECK(num_samples == 80 || num_samples == 160);
 #if defined(WEBRTC_UNTRUSTED_DELAY)
   reported_delay_ms = kFixedDelayMs;
 #else