Enable probing with repeated payload packets by default.

webrtc/modules/video_coding/main/source/jitter_buffer.cc

 /*
  *  Copyright (c) 2012 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.
  */
 #include "webrtc/modules/video_coding/main/source/jitter_buffer.h"
@@ skipping 896 matching lines @@
 }
 
 std::vector<uint16_t> VCMJitterBuffer::GetNackList(bool* request_key_frame) {
   CriticalSectionScoped cs(crit_sect_);
   *request_key_frame = false;
   if (nack_mode_ == kNoNack) {
     return std::vector<uint16_t>();
   }
   if (last_decoded_state_.in_initial_state()) {
     VCMFrameBuffer* next_frame = NextFrame();
+    if (!next_frame)
+      return std::vector<uint16_t>();
     const bool first_frame_is_key = next_frame &&
         next_frame->FrameType() == kVideoFrameKey &&
         next_frame->HaveFirstPacket();
     if (!first_frame_is_key) {
       bool have_non_empty_frame = decodable_frames_.end() != find_if(
           decodable_frames_.begin(), decodable_frames_.end(),
           HasNonEmptyState);
       if (!have_non_empty_frame) {
         have_non_empty_frame = incomplete_frames_.end() != find_if(
             incomplete_frames_.begin(), incomplete_frames_.end(),
@@ skipping 326 matching lines @@
   }
   // Evaluate if the RTT is higher than |high_rtt_nack_threshold_ms_|, and in
   // that case we don't wait for retransmissions.
   if (high_rtt_nack_threshold_ms_ >= 0 &&
       rtt_ms_ >= high_rtt_nack_threshold_ms_) {
     return false;
   }
   return true;
 }
 }  // namespace webrtc