Get rid of packet loss related stuff from videoprocessor.

This feature is not needed in video codec testing framework. In WebRTC
video codecs never deal with packet loss. Packet loss is handled by
jitter buffer which prevents passing of incomplete frames to decoder.

Bug: webrtc:8768
Change-Id: I211cf51d913bec6a1f935e30691661d428ebd3b6
Reviewed-on: https://webrtc-review.googlesource.com/40740
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21722}

modules/video_coding/codecs/test/stats.h

@@ -57,11 +57,6 @@ struct FrameStatistic {
   // Quantization.
   int qp = -1;
 
-  // How many packets were discarded of the encoded frame data (if any).
-  size_t packets_dropped = 0;
-  size_t total_packets = 0;
-  size_t manipulated_length = 0;
-
   // Quality.
   float psnr = 0.0;
   float ssim = 0.0;