Expose Ivf logging through the native API

webrtc/video/video_loopback.cc

Index: webrtc/video/video_loopback.cc
diff --git a/webrtc/video/video_loopback.cc b/webrtc/video/video_loopback.cc
index 10998c8867131362d26cd0b18c49921204f9877d..da73640b4450fdfc63f1a7c9e49692fd828e92fb 100644
--- a/webrtc/video/video_loopback.cc
+++ b/webrtc/video/video_loopback.cc
@@ -183,6 +183,14 @@ std::string SL1() {
   return static_cast<std::string>(FLAGS_sl1);
 }
 
+DEFINE_string(encoded_frame_path,
+              "",
+              "The base path for encoded frame logs. Created files will have "
+              "the form <encoded_frame_path>.<n>.(recv|send.<m>).ivf");
+std::string EncodedFramePath() {
+  return static_cast<std::string>(FLAGS_encoded_frame_path);
+}
+
 DEFINE_bool(logs, false, "print logs to stderr");
 
 DEFINE_bool(send_side_bwe, true, "Use send-side bandwidth estimation");
@@ -230,12 +238,21 @@ void Loopback() {
   call_bitrate_config.max_bitrate_bps = flags::MaxBitrateKbps() * 1000;
 
   VideoQualityTest::Params params;
-  params.common = {flags::Width(), flags::Height(), flags::Fps(),
-      flags::MinBitrateKbps() * 1000, flags::TargetBitrateKbps() * 1000,
-      flags::MaxBitrateKbps() * 1000, flags::FLAGS_suspend_below_min_bitrate,
-      flags::Codec(), flags::NumTemporalLayers(), flags::SelectedTL(),
-      0,  // No min transmit bitrate.
-      flags::FLAGS_send_side_bwe, flags::FLAGS_use_fec, call_bitrate_config};
+  params.common = {flags::Width(),
+                   flags::Height(),
+                   flags::Fps(),
+                   flags::MinBitrateKbps() * 1000,
+                   flags::TargetBitrateKbps() * 1000,
+                   flags::MaxBitrateKbps() * 1000,
+                   flags::FLAGS_suspend_below_min_bitrate,
+                   flags::Codec(),
+                   flags::NumTemporalLayers(),
+                   flags::SelectedTL(),
+                   0,  // No min transmit bitrate.
+                   flags::FLAGS_send_side_bwe,
+                   flags::FLAGS_use_fec,
+                   flags::EncodedFramePath(),
+                   call_bitrate_config};
   params.video = {flags::Clip()};
   params.analyzer = {"video", 0.0, 0.0, flags::DurationSecs(),
       flags::OutputFilename(), flags::GraphTitle()};