AEC3: Refactor the code for analyzing filter convergence

This CL refactors the code in AEC3 that analyzes how
well the adaptive filter performs. The purpose of this
is both to simplify code that is more complex than needed
and also to pave the wave for the upcoming CLs that
softens the echo suppression during doubletalk.

The main changes are that:
-The shadow adaptive filter is now never analyzed. This
turned out to never affect the output in the recordings
it was tested on.
-The convergence analysis was moved to the aec state
code.

The changes are bitexact on all testcases where they
have been tested on.

Bug: webrtc:8671
Change-Id: If76b669565325c8eb4d11d1178a7e20306da9a26
Reviewed-on: https://webrtc-review.googlesource.com/87430
Commit-Queue: Per Åhgren <peah@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23958}

modules/audio_processing/aec3/aec_state.h

@@ -29,6 +29,8 @@
 #include "modules/audio_processing/aec3/filter_analyzer.h"
 #include "modules/audio_processing/aec3/render_buffer.h"
 #include "modules/audio_processing/aec3/reverb_model_estimator.h"
+#include "modules/audio_processing/aec3/subtractor_output.h"
+#include "modules/audio_processing/aec3/subtractor_output_analyzer.h"
 #include "modules/audio_processing/aec3/suppression_gain_limiter.h"
 #include "rtc_base/constructormagic.h"
 
@@ -151,12 +153,11 @@ class AecState {
               const std::vector<std::array<float, kFftLengthBy2Plus1>>&
                   adaptive_filter_frequency_response,
               const std::vector<float>& adaptive_filter_impulse_response,
-              bool converged_filter,
-              bool diverged_filter,
               const RenderBuffer& render_buffer,
               const std::array<float, kFftLengthBy2Plus1>& E2_main,
               const std::array<float, kFftLengthBy2Plus1>& Y2,
-              const std::array<float, kBlockSize>& s);
+              const SubtractorOutput& subtractor_output,
+              rtc::ArrayView<const float> y);
 
   // Returns the tail freq. response of the linear filter.
   rtc::ArrayView<const float> GetFreqRespTail() const {
@@ -218,6 +219,7 @@ class AecState {
   size_t active_blocks_since_converged_filter_ = 0;
   EchoAudibility echo_audibility_;
   ReverbModelEstimator reverb_model_estimator_;
+  SubtractorOutputAnalyzer subtractor_output_analyzer_;
   RTC_DISALLOW_COPY_AND_ASSIGN(AecState);
 };