Allow residual echo detector to be enabled/disabled using AudioOptions, and no longer disable it on…

webrtc/media/engine/webrtcvoiceengine.cc

Index: webrtc/media/engine/webrtcvoiceengine.cc
diff --git a/webrtc/media/engine/webrtcvoiceengine.cc b/webrtc/media/engine/webrtcvoiceengine.cc
index 2db552611220775e67f4f82a936ec949d2b01934..9096154c17f5e4b36b7b9b96bc24c4c036e3c220 100644
--- a/webrtc/media/engine/webrtcvoiceengine.cc
+++ b/webrtc/media/engine/webrtcvoiceengine.cc
@@ -643,13 +643,7 @@ WebRtcVoiceEngine::WebRtcVoiceEngine(
     options.experimental_ns = rtc::Optional<bool>(false);
     options.intelligibility_enhancer = rtc::Optional<bool>(false);
     options.level_control = rtc::Optional<bool>(false);
-// TODO(ivoc): Always enable residual echo detector after benchmarking on
-//             mobile.
-#if defined(WEBRTC_ANDROID) || defined(WEBRTC_IOS)
-    options.residual_echo_detector = rtc::Optional<bool>(false);
-#else
     options.residual_echo_detector = rtc::Optional<bool>(true);
-#endif
     bool error = ApplyOptions(options);
     RTC_DCHECK(error);
   }
@@ -714,7 +708,6 @@ bool WebRtcVoiceEngine::ApplyOptions(const AudioOptions& options_in) {
   options.experimental_agc = rtc::Optional<bool>(false);
   options.extended_filter_aec = rtc::Optional<bool>(false);
   options.experimental_ns = rtc::Optional<bool>(false);
-  options.residual_echo_detector = rtc::Optional<bool>(false);
 #endif
 
   // Delay Agnostic AEC automatically turns on EC if not set except on iOS
@@ -947,6 +940,11 @@ bool WebRtcVoiceEngine::ApplyOptions(const AudioOptions& options_in) {
     apm_config_.high_pass_filter.enabled = *options.highpass_filter;
   }
 
+  if (options.residual_echo_detector) {
+    apm_config_.residual_echo_detector.enabled =
+        *options.residual_echo_detector;
+  }
+
   apm()->SetExtraOptions(config);
   apm()->ApplyConfig(apm_config_);