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

webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc

Index: webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc
diff --git a/webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc b/webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc
index 4df8aeaaca2091b55eef61b88022ec1319370afd..1e17f111185c0ee458473ba88a1d42e3255319ff 100644
--- a/webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc
+++ b/webrtc/modules/audio_processing/aec3/echo_canceller3_unittest.cc
@@ -715,6 +715,12 @@ TEST(EchoCanceller3InputCheck, NullCaptureProcessingParameter) {
   EXPECT_DEATH(EchoCanceller3(8000, false).ProcessCapture(nullptr, false), "");
 }
 
+// Verifies the check for correct sample rate.
+TEST(EchoCanceller3InputCheck, WrongSampleRate) {
+  ApmDataDumper data_dumper(0);
+  EXPECT_DEATH(EchoCanceller3(8001, false), "");
+}
+
 #endif
 
 }  // namespace webrtc