Add algorithm for Residual Echo Detector.

webrtc/modules/BUILD.gn

 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("../build/webrtc.gni")
 import("audio_coding/audio_coding.gni")
@@ skipping 565 matching lines @@
         "audio_coding:neteq_unittest_proto",
         "audio_processing:audioproc_protobuf_utils",
         "audio_processing:audioproc_unittest_proto",
       ]
       sources += [
         "audio_processing/audio_processing_impl_locking_unittest.cc",
         "audio_processing/audio_processing_impl_unittest.cc",
         "audio_processing/audio_processing_unittest.cc",
         "audio_processing/echo_cancellation_bit_exact_unittest.cc",
         "audio_processing/echo_control_mobile_unittest.cc",
+        "audio_processing/echo_detector/circular_buffer_unittest.cc",
+        "audio_processing/echo_detector/echo_detector_unittest.cc",
+        "audio_processing/echo_detector/mean_variance_estimator_unittest.cc",
+        "audio_processing/echo_detector/normalized_covariance_estimator_unittest.cc",
         "audio_processing/gain_control_unittest.cc",
         "audio_processing/high_pass_filter_unittest.cc",
         "audio_processing/level_controller/level_controller_unittest.cc",
         "audio_processing/level_estimator_unittest.cc",
         "audio_processing/noise_suppression_unittest.cc",
         "audio_processing/test/bitexactness_tools.cc",
         "audio_processing/test/bitexactness_tools.h",
         "audio_processing/test/debug_dump_replayer.cc",
         "audio_processing/test/debug_dump_replayer.h",
         "audio_processing/test/debug_dump_test.cc",
@@ skipping 135 matching lines @@
       "../test:test_common",
       "../test:test_support_main",
       "remote_bitrate_estimator:bwe_simulator_lib",
       "video_capture",
       "//testing/gmock",
       "//testing/gtest",
       "//third_party/gflags",
     ]
   }
 }