Make FakeDecodeFromFile handle codec-internal CNG

webrtc/modules/audio_coding/neteq/tools/neteq_packet_source_input.cc

 /*
  *  Copyright (c) 2016 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 25 matching lines @@
 void NetEqPacketSourceInput::LoadNextPacket() {
   packet_ = source()->NextPacket();
 }
 
 std::unique_ptr<NetEqInput::PacketData> NetEqPacketSourceInput::PopPacket() {
   if (!packet_) {
     return std::unique_ptr<PacketData>();
   }
   std::unique_ptr<PacketData> packet_data(new PacketData);
   packet_->ConvertHeader(&packet_data->header);
-  packet_data->payload.SetData(packet_->payload(),
-                               packet_->payload_length_bytes());
+  if (packet_->payload_length_bytes() == 0 &&
+      packet_->virtual_payload_length_bytes() > 0) {
+    // This is a header-only "dummy" packet. Set the payload to all zeros, with
+    // length according to the virtual length.
+    packet_data->payload.SetSize(packet_->virtual_payload_length_bytes());
+    std::fill_n(packet_data->payload.data(), packet_data->payload.size(), 0);
+  } else {
+    packet_data->payload.SetData(packet_->payload(),
+                                 packet_->payload_length_bytes());
+  }
   packet_data->time_ms = packet_->time_ms();
 
   LoadNextPacket();
 
   return packet_data;
 }
 
 NetEqRtpDumpInput::NetEqRtpDumpInput(const std::string& file_name)
     : source_(RtpFileSource::Create(file_name)) {
   LoadNextPacket();
@@ skipping 33 matching lines @@
     next_output_event_ms_ = rtc::Optional<int64_t>();
   }
 }
 
 PacketSource* NetEqEventLogInput::source() {
   return source_.get();
 }
 
 }  // namespace test
 }  // namespace webrtc