Adding test for SingleNalUnit mode

modules/video_coding/codecs/test/stats.h

 /*
  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 14 matching lines @@
 
   // Encoding.
   int64_t encode_start_ns = 0;
   int encode_return_code = 0;
   bool encoding_successful = false;
   int encode_time_us = 0;
   int bitrate_kbps = 0;
   size_t encoded_frame_size_bytes = 0;
   webrtc::FrameType frame_type = kVideoFrameDelta;
 
+  // H264 specific.
+  rtc::Optional<size_t> max_nalu_length;
+
   // Decoding.
   int64_t decode_start_ns = 0;
   int decode_return_code = 0;
   bool decoding_successful = false;
   int decode_time_us = 0;
   int decoded_width = 0;
   int decoded_height = 0;
 
   // Quantization.
   int qp = -1;
@@ skipping 22 matching lines @@
   void PrintSummary() const;
 
  private:
   std::vector<FrameStatistic> stats_;
 };
 
 }  // namespace test
 }  // namespace webrtc
 
 #endif  // MODULES_VIDEO_CODING_CODECS_TEST_STATS_H_