Wire up bandwidth limitation info to GetStats and adapt_reason.

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 2138 matching lines @@
                             &last_captured_frame_format);
         info.input_frame_width = last_captured_frame_format.width;
         info.input_frame_height = last_captured_frame_format.height;
       }
       if (capturer_->video_adapter() != nullptr) {
         info.adapt_changes += capturer_->video_adapter()->adaptation_changes();
         info.adapt_reason = capturer_->video_adapter()->adapt_reason();
       }
     }
   }
+
+  // Get bandwidth limitation info from stream_->GetStats().
+  // Input resolution (output from video_adapter) can be further scaled down or
+  // higher video layer(s) can be dropped due to bitrate constraints.
+  // Note, adapt_changes only include changes from the video_adapter.
+  if (stats.bw_limited_resolution)
+    info.adapt_reason = CoordinatedVideoAdapter::ADAPTREASON_BANDWIDTH;

[stefan-webrtc, 2015/12/07 16:02:33]

Now this may overwrite any reason written on line 2155. Should we handle
multiple adapt reasons? Maybe not needed for now, but could be worth commenting
on.

[åsapersson, 2015/12/08 08:58:25]

The video_adapter shows the most limiting reason (or several if having the same
limit). Updated comment that BW will be the most limiting if set and therefore
overwritten.

[åsapersson, 2015/12/11 14:39:38]

Have changed so BW is added (and does not overwrite reasons from video adapter).
PTAL.  

+
   info.ssrc_groups = ssrc_groups_;
   info.framerate_input = stats.input_frame_rate;
   info.framerate_sent = stats.encode_frame_rate;
   info.avg_encode_ms = stats.avg_encode_time_ms;
   info.encode_usage_percent = stats.encode_usage_percent;
 
   info.nominal_bitrate = stats.media_bitrate_bps;
 
   info.send_frame_width = 0;
   info.send_frame_height = 0;
@@ skipping 514 matching lines @@
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket
 
 #endif  // HAVE_WEBRTC_VIDEO