Add a simple, safe gain PostProcessor.

chromecast/media/service/cast_renderer.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chromecast/media/service/cast_renderer.h"
 
 #include "base/bind.h"
 #include "base/single_thread_task_runner.h"
 #include "chromecast/base/task_runner_impl.h"
 #include "chromecast/media/base/audio_device_ids.h"
@@ skipping 90 matching lines @@
   // TODO(erickung): crbug.com/443956. Need to provide right LoadType.
   LoadType load_type = kLoadTypeMediaSource;
   MediaPipelineDeviceParams::MediaSyncType sync_type =
       (load_type == kLoadTypeMediaStream)
           ? MediaPipelineDeviceParams::kModeIgnorePts
           : MediaPipelineDeviceParams::kModeSyncPts;
 
   AudioContentType content_type;
   if (audio_device_id_ == kAlarmAudioDeviceId) {
     content_type = AudioContentType::kAlarm;
-  } else if (audio_device_id_ == kTtsAudioDeviceId) {
+  } else if (audio_device_id_ == kTtsAudioDeviceId ||
+             audio_device_id_ ==
+                 ::media::AudioDeviceDescription::kCommunicationsDeviceId) {
     content_type = AudioContentType::kCommunication;
   } else {
     content_type = AudioContentType::kMedia;
   }
   MediaPipelineDeviceParams params(sync_type, backend_task_runner_.get(),
                                    content_type, audio_device_id_);
 
   if (audio_device_id_ == kTtsAudioDeviceId ||
       audio_device_id_ ==
           ::media::AudioDeviceDescription::kCommunicationsDeviceId) {
@@ skipping 226 matching lines @@
 }
 
 void CastRenderer::OnVideoOpacityChange(bool opaque) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(opaque);
   client_->OnVideoOpacityChange(opaque);
 }
 
 }  // namespace media
 }  // namespace chromecast