Delete nack_enabled flag in encoder configuration.

This is a followup to cl https://webrtc-review.googlesource.com/71380,
which reworked the way encoder resilience is done, and made the
nack_enabled flag unused.

Bug: webrtc:8830
Change-Id: I3de2508c97bc71e01c8f2232d16cd1f33e57fe4a
Reviewed-on: https://webrtc-review.googlesource.com/69986
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23080}
diff --git a/modules/video_coding/include/video_codec_initializer.h b/modules/video_coding/include/video_codec_initializer.h
index 0748db0..fa2582f 100644
--- a/modules/video_coding/include/video_codec_initializer.h
+++ b/modules/video_coding/include/video_codec_initializer.h
@@ -34,10 +34,20 @@
   static bool SetupCodec(
       const VideoEncoderConfig& config,
       const std::vector<VideoStream>& streams,
-      bool nack_enabled,
       VideoCodec* codec,
       std::unique_ptr<VideoBitrateAllocator>* bitrate_allocator);
 
+  // TODO(nisse): Deprecated, delete as soon as downstream projects are
+  // updated.
+  static bool SetupCodec(
+      const VideoEncoderConfig& config,
+      const std::vector<VideoStream>& streams,
+      bool /* nack_enabled */,
+      VideoCodec* codec,
+      std::unique_ptr<VideoBitrateAllocator>* bitrate_allocator) {
+    return SetupCodec(config, streams, codec, bitrate_allocator);
+  }
+
   // Create a bitrate allocator for the specified codec.
   static std::unique_ptr<VideoBitrateAllocator> CreateBitrateAllocator(
       const VideoCodec& codec);
@@ -45,8 +55,7 @@
  private:
   static VideoCodec VideoEncoderConfigToVideoCodec(
       const VideoEncoderConfig& config,
-      const std::vector<VideoStream>& streams,
-      bool nack_enabled);
+      const std::vector<VideoStream>& streams);
 };
 
 }  // namespace webrtc
diff --git a/modules/video_coding/video_codec_initializer.cc b/modules/video_coding/video_codec_initializer.cc
index 34fcb8d..192f80f 100644
--- a/modules/video_coding/video_codec_initializer.cc
+++ b/modules/video_coding/video_codec_initializer.cc
@@ -29,13 +29,12 @@
 bool VideoCodecInitializer::SetupCodec(
     const VideoEncoderConfig& config,
     const std::vector<VideoStream>& streams,
-    bool nack_enabled,
     VideoCodec* codec,
     std::unique_ptr<VideoBitrateAllocator>* bitrate_allocator) {
   if (config.codec_type == kVideoCodecMultiplex) {
     VideoEncoderConfig associated_config = config.Copy();
     associated_config.codec_type = kVideoCodecVP9;
-    if (!SetupCodec(associated_config, streams, nack_enabled, codec,
+    if (!SetupCodec(associated_config, streams, codec,
                     bitrate_allocator)) {
       RTC_LOG(LS_ERROR) << "Failed to create stereo encoder configuration.";
       return false;
@@ -45,7 +44,7 @@
   }
 
   *codec =
-      VideoEncoderConfigToVideoCodec(config, streams, nack_enabled);
+      VideoEncoderConfigToVideoCodec(config, streams);
   *bitrate_allocator = CreateBitrateAllocator(*codec);
 
   return true;
@@ -73,8 +72,7 @@
 // TODO(sprang): Split this up and separate the codec specific parts.
 VideoCodec VideoCodecInitializer::VideoEncoderConfigToVideoCodec(
     const VideoEncoderConfig& config,
-    const std::vector<VideoStream>& streams,
-    bool nack_enabled) {
+    const std::vector<VideoStream>& streams) {
   static const int kEncoderMinBitrateKbps = 30;
   RTC_DCHECK(!streams.empty());
   RTC_DCHECK_GE(config.min_transmit_bitrate_bps, 0);
diff --git a/modules/video_coding/video_codec_initializer_unittest.cc b/modules/video_coding/video_codec_initializer_unittest.cc
index 2ef1159..104b149 100644
--- a/modules/video_coding/video_codec_initializer_unittest.cc
+++ b/modules/video_coding/video_codec_initializer_unittest.cc
@@ -39,7 +39,7 @@
 // TODO(sprang): Extend coverage to handle the rest of the codec initializer.
 class VideoCodecInitializerTest : public ::testing::Test {
  public:
-  VideoCodecInitializerTest() : nack_enabled_(false) {}
+  VideoCodecInitializerTest() {}
   virtual ~VideoCodecInitializerTest() {}
 
  protected:
@@ -76,7 +76,7 @@
     codec_out_ = VideoCodec();
     bitrate_allocator_out_.reset();
     temporal_layers_.clear();
-    if (!VideoCodecInitializer::SetupCodec(config_, streams_, nack_enabled_,
+    if (!VideoCodecInitializer::SetupCodec(config_, streams_,
                                            &codec_out_,
                                            &bitrate_allocator_out_)) {
       return false;
@@ -122,7 +122,6 @@
   // Input settings.
   VideoEncoderConfig config_;
   std::vector<VideoStream> streams_;
-  bool nack_enabled_;
 
   // Output.
   VideoCodec codec_out_;