Add separate send-side UMA stats for screenshare and video.

talk/media/webrtc/webrtcvideoengine2.cc

 /*
  * libjingle
  * Copyright 2014 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 2124 matching lines @@
 
 void WebRtcVideoChannel2::WebRtcVideoSendStream::SetDimensions(
     int width,
     int height,
     bool is_screencast) {
   if (last_dimensions_.width == width && last_dimensions_.height == height &&
       last_dimensions_.is_screencast == is_screencast) {
     // Configured using the same parameters, do not reconfigure.
     return;
   }
+  bool switched_content_type = last_dimensions_.is_screencast != is_screencast;
   LOG(LS_INFO) << "SetDimensions: " << width << "x" << height
                << (is_screencast ? " (screencast)" : " (not screencast)");
 
   last_dimensions_.width = width;
   last_dimensions_.height = height;
   last_dimensions_.is_screencast = is_screencast;
 
+  if (switched_content_type) {
+    // If we change content type, reset entire stream so that state is reset
+    // (stats flushed etc).
+    RecreateWebRtcStream();

[mflodman, 2015/12/02 08:59:13]

As I read the code, this will generate a new sequence number and timestamp base
for the same ssrc and srtp instance and won't work well.

[mflodman, 2015/12/02 09:12:25]

Now I agree this seems to work, given the magic in VideoSendStream. I'd still
like to discuss this though.

+  }
+
   RTC_DCHECK(!parameters_.encoder_config.streams.empty());
 
   RTC_CHECK(parameters_.codec_settings);
   VideoCodecSettings codec_settings = *parameters_.codec_settings;
 
   webrtc::VideoEncoderConfig encoder_config =
       CreateVideoEncoderConfig(last_dimensions_, codec_settings.codec);
 
   encoder_config.encoder_specific_settings = ConfigureVideoEncoderSettings(
       codec_settings.codec, parameters_.options, is_screencast);
@@ skipping 582 matching lines @@
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket
 
 #endif  // HAVE_WEBRTC_VIDEO