WebRTC AGC2: explicitly enable adaptive digital mode.

The default APM configuration will change disabling the adaptive digital
mode of AGC2.

Bug: webrtc:7494
Change-Id: I272153142dcd49b267feeb2620a651d42db62e01
Reviewed-on: https://chromium-review.googlesource.com/c/1345437Reviewed-by: Max Morin <maxmorin@chromium.org>
Commit-Queue: Ale Bzk <alessiob@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610031}

content/renderer/media/stream/media_stream_audio_processor.cc

@@ -674,6 +674,8 @@ void MediaStreamAudioProcessor::InitializeAudioProcessingModule(
         base::FeatureList::IsEnabled(features::kWebRtcHybridAgc);
     apm_config.gain_controller2.fixed_digital.gain_db = 0.f;
 
+    apm_config.gain_controller2.adaptive_digital.enabled = true;
+
     const bool use_peaks_not_rms = base::GetFieldTrialParamByFeatureAsBool(
         features::kWebRtcHybridAgc, "use_peaks_not_rms", false);
     using Shortcut =

media/webrtc/audio_processor.cc

@@ -315,6 +315,7 @@ void AudioProcessor::InitializeAPM() {
         settings_.automatic_gain_control ==
         AutomaticGainControlType::kHybridExperimental;
     apm_config.gain_controller2.fixed_digital.gain_db = 0.f;
+    apm_config.gain_controller2.adaptive_digital.enabled = true;
     const bool use_peaks_not_rms = base::GetFieldTrialParamByFeatureAsBool(
         features::kWebRtcHybridAgc, "use_peaks_not_rms", false);
     using Shortcut =