Adding full initial version of delay estimation functionality in echo canceller 3

webrtc/modules/audio_processing/aec3/block_processor.cc

Index: webrtc/modules/audio_processing/aec3/block_processor.cc
diff --git a/webrtc/modules/audio_processing/aec3/block_processor.cc b/webrtc/modules/audio_processing/aec3/block_processor.cc
index 2a5471a984597a34ac42e1f7b55221125a7fd820..9743db9f132d5edaa38e10262debf608780320d6 100644
--- a/webrtc/modules/audio_processing/aec3/block_processor.cc
+++ b/webrtc/modules/audio_processing/aec3/block_processor.cc
@@ -64,7 +64,9 @@ BlockProcessorImpl::BlockProcessorImpl(
       sample_rate_hz_(sample_rate_hz),
       render_buffer_(std::move(render_buffer)),
       delay_controller_(std::move(delay_controller)),
-      echo_remover_(std::move(echo_remover)) {}
+      echo_remover_(std::move(echo_remover)) {
+  RTC_DCHECK(ValidFullBandRate(sample_rate_hz_));
+}
 
 BlockProcessorImpl::~BlockProcessorImpl() = default;