Revert "Remove APM internal usage of EchoCancellation"

This reverts commit 1a03960e632a04e2ff866f2048cc36146af83e41.

Reason for revert: breaks downstream projects.

Original change's description:
> Remove APM internal usage of EchoCancellation
> 
> This CL:
>  - Changes EchoCancellationImpl to inherit privately from
>    EchoCancellation.
>  - Removes usage of AudioProcessing::echo_cancellation() inside most of
>    the audio processing module and unit tests.
>  - Default-enables metrics collection in AEC2.
> 
> This CL breaks audioproc_f backwards compatibility: It can no longer
> use all recorded settings (drift compensation, suppression level), but
> prints an error message when such settings are encountered.
> 
> Some code in audio_processing_unittest.cc still uses the old interface.
> I'll handle that in a separate change, as it is not as straightforward
> to preserve coverage.
> 
> Bug: webrtc:9535
> Change-Id: Ia4d4b8d117ccbe516e5345c15d37298418590686
> Reviewed-on: https://webrtc-review.googlesource.com/97603
> Commit-Queue: Sam Zackrisson <saza@webrtc.org>
> Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#24724}

TBR=gustaf@webrtc.org,saza@webrtc.org

Change-Id: Ifdc4235f9c5ee8a8a5d32cc8e1dda0853b941693
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9535
Reviewed-on: https://webrtc-review.googlesource.com/100305
Reviewed-by: Sergey Silkin <ssilkin@webrtc.org>
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24729}
diff --git a/modules/audio_processing/test/debug_dump_replayer.cc b/modules/audio_processing/test/debug_dump_replayer.cc
index 94d03d3..6350c8c 100644
--- a/modules/audio_processing/test/debug_dump_replayer.cc
+++ b/modules/audio_processing/test/debug_dump_replayer.cc
@@ -123,6 +123,7 @@
   RTC_CHECK_EQ(AudioProcessing::kNoError,
                apm_->set_stream_delay_ms(msg.delay()));
 
+  apm_->echo_cancellation()->set_stream_drift_samples(msg.drift());
   if (msg.has_keypress()) {
     apm_->set_stream_key_pressed(msg.keypress());
   } else {
@@ -212,11 +213,16 @@
   apm_config.echo_canceller.enabled = msg.aec_enabled() || msg.aecm_enabled();
   apm_config.echo_canceller.mobile_mode = msg.aecm_enabled();
 
+  RTC_CHECK(msg.has_aec_drift_compensation_enabled());
+  RTC_CHECK_EQ(AudioProcessing::kNoError,
+               apm_->echo_cancellation()->enable_drift_compensation(
+                   msg.aec_drift_compensation_enabled()));
+
   RTC_CHECK(msg.has_aec_suppression_level());
-  apm_config.echo_canceller.legacy_moderate_suppression_level =
-      static_cast<EchoCancellation::SuppressionLevel>(
-          msg.aec_suppression_level()) ==
-      EchoCancellation::SuppressionLevel::kModerateSuppression;
+  RTC_CHECK_EQ(AudioProcessing::kNoError,
+               apm_->echo_cancellation()->set_suppression_level(
+                   static_cast<EchoCancellation::SuppressionLevel>(
+                       msg.aec_suppression_level())));
 
   RTC_CHECK(msg.has_aecm_comfort_noise_enabled());
   RTC_CHECK_EQ(AudioProcessing::kNoError,