Introduce struct MediaConfig, with construction-time settings.

webrtc/media/webrtc/webrtcvideoengine2.cc

Index: webrtc/media/webrtc/webrtcvideoengine2.cc
diff --git a/webrtc/media/webrtc/webrtcvideoengine2.cc b/webrtc/media/webrtc/webrtcvideoengine2.cc
index 265aa12108fb8a48df1605228ad8f09da0137eb5..a4348989a44017f4ef9032c3db5be34114a2769b 100644
--- a/webrtc/media/webrtc/webrtcvideoengine2.cc
+++ b/webrtc/media/webrtc/webrtcvideoengine2.cc
@@ -52,6 +52,9 @@
 #include "webrtc/video_decoder.h"
 #include "webrtc/video_encoder.h"
 
+// TODO(nisse): Improper include? Move declaration of MediaConfig elsewhere?
+#include "talk/app/webrtc/mediacontroller.h"
+
 namespace cricket {
 namespace {
 
@@ -526,10 +529,11 @@ void WebRtcVideoEngine2::Init() {
 
 WebRtcVideoChannel2* WebRtcVideoEngine2::CreateChannel(
     webrtc::Call* call,
+    const webrtc::MediaConfig& config,
     const VideoOptions& options) {
   RTC_DCHECK(initialized_);
   LOG(LS_INFO) << "CreateChannel. Options: " << options.ToString();
-  return new WebRtcVideoChannel2(call, options, video_codecs_,
+  return new WebRtcVideoChannel2(call, config, options, video_codecs_,
       external_encoder_factory_, external_decoder_factory_);
 }
 
@@ -619,19 +623,19 @@ std::vector<VideoCodec> WebRtcVideoEngine2::GetSupportedCodecs() const {
 
 WebRtcVideoChannel2::WebRtcVideoChannel2(
     webrtc::Call* call,
+    const webrtc::MediaConfig& config,
     const VideoOptions& options,
     const std::vector<VideoCodec>& recv_codecs,
     WebRtcVideoEncoderFactory* external_encoder_factory,
     WebRtcVideoDecoderFactory* external_decoder_factory)
-    : call_(call),
+    : VideoMediaChannel(config), call_(call),
       unsignalled_ssrc_handler_(&default_unsignalled_ssrc_handler_),
       external_encoder_factory_(external_encoder_factory),
       external_decoder_factory_(external_decoder_factory) {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
-  SetDefaultOptions();
   options_.SetAll(options);
-  if (options_.cpu_overuse_detection)
-    signal_cpu_adaptation_ = *options_.cpu_overuse_detection;
+  signal_cpu_adaptation_ = config.cpu_overuse_detection;
+  disable_prerenderer_smoothing_ = config.disable_prerenderer_smoothing;
   rtcp_receiver_report_ssrc_ = kDefaultRtcpReceiverReportSsrc;
   sending_ = false;
   default_send_ssrc_ = 0;
@@ -639,13 +643,6 @@ WebRtcVideoChannel2::WebRtcVideoChannel2(
   recv_codecs_ = FilterSupportedCodecs(MapCodecs(recv_codecs));
 }
 
-void WebRtcVideoChannel2::SetDefaultOptions() {
-  options_.cpu_overuse_detection = rtc::Optional<bool>(true);
-  options_.dscp = rtc::Optional<bool>(false);
-  options_.suspend_below_min_bitrate = rtc::Optional<bool>(false);
-  options_.screencast_min_bitrate_kbps = rtc::Optional<int>(0);
-}
-
 WebRtcVideoChannel2::~WebRtcVideoChannel2() {
   for (auto& kv : send_streams_)
     delete kv.second;
@@ -774,6 +771,10 @@ bool WebRtcVideoChannel2::GetChangedSendParameters(
   return true;
 }
 
+rtc::DiffServCodePoint WebRtcVideoChannel2::MediaTypeDscpValue() const {
+  return rtc::DSCP_AF41;
+}
+
 bool WebRtcVideoChannel2::SetSendParameters(const VideoSendParameters& params) {
   TRACE_EVENT0("webrtc", "WebRtcVideoChannel2::SetSendParameters");
   LOG(LS_INFO) << "SetSendParameters: " << params.ToString();
@@ -818,18 +819,8 @@ bool WebRtcVideoChannel2::SetSendParameters(const VideoSendParameters& params) {
     call_->SetBitrateConfig(bitrate_config_);
   }
 
-  if (changed_params.options) {
+  if (changed_params.options)
     options_.SetAll(*changed_params.options);
-    {
-      rtc::CritScope lock(&capturer_crit_);
-      if (options_.cpu_overuse_detection) {
-        signal_cpu_adaptation_ = *options_.cpu_overuse_detection;
-      }
-    }
-    rtc::DiffServCodePoint dscp =
-        options_.dscp.value_or(false) ? rtc::DSCP_AF41 : rtc::DSCP_DEFAULT;
-    MediaChannel::SetDscp(dscp);
-  }
 
   {
     rtc::CritScope stream_lock(&stream_crit_);
@@ -1155,7 +1146,7 @@ bool WebRtcVideoChannel2::AddRecvStream(const StreamParams& sp,
 
   receive_streams_[ssrc] = new WebRtcVideoReceiveStream(
       call_, sp, config, external_decoder_factory_, default_stream,
-      recv_codecs_, options_.disable_prerenderer_smoothing.value_or(false));
+      recv_codecs_, disable_prerenderer_smoothing_);
 
   return true;
 }
@@ -1791,9 +1782,8 @@ void WebRtcVideoChannel2::WebRtcVideoSendStream::SetCodecAndOptions(
   parameters_.config.rtp.nack.rtp_history_ms =
       HasNack(codec_settings.codec) ? kNackHistoryMs : 0;
 
-  RTC_CHECK(options.suspend_below_min_bitrate);
   parameters_.config.suspend_below_min_bitrate =
-      *options.suspend_below_min_bitrate;
+      options.suspend_below_min_bitrate.value_or(false);
 
   parameters_.codec_settings =
       rtc::Optional<WebRtcVideoChannel2::VideoCodecSettings>(codec_settings);
@@ -1859,9 +1849,8 @@ WebRtcVideoChannel2::WebRtcVideoSendStream::CreateVideoEncoderConfig(
     const VideoCodec& codec) const {
   webrtc::VideoEncoderConfig encoder_config;
   if (dimensions.is_screencast) {
-    RTC_CHECK(parameters_.options.screencast_min_bitrate_kbps);
     encoder_config.min_transmit_bitrate_bps =
-        *parameters_.options.screencast_min_bitrate_kbps * 1000;
+        1000 * parameters_.options.screencast_min_bitrate_kbps.value_or(0);
     encoder_config.content_type =
         webrtc::VideoEncoderConfig::ContentType::kScreen;
   } else {