Adding partial authentication of the Generic RTP Frame Descriptor.

Bug: None
Change-Id: I590e28acbd17b45dcb4e3bac34d223ad0903f7dc
Reviewed-on: https://webrtc-review.googlesource.com/c/113131
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25921}
diff --git a/modules/rtp_rtcp/source/rtp_sender_video.cc b/modules/rtp_rtcp/source/rtp_sender_video.cc
index b35e598..bb4faa0 100644
--- a/modules/rtp_rtcp/source/rtp_sender_video.cc
+++ b/modules/rtp_rtcp/source/rtp_sender_video.cc
@@ -513,7 +513,7 @@
     size_t bytes_written = 0;
     if (frame_encryptor_->Encrypt(
             cricket::MEDIA_TYPE_VIDEO, first_packet->Ssrc(),
-            /*additional_data=*/nullptr,
+            generic_descriptor_raw,
             rtc::MakeArrayView(payload_data, payload_size),
             encrypted_video_payload, &bytes_written) != 0) {
       return false;
diff --git a/video/buffered_frame_decryptor.cc b/video/buffered_frame_decryptor.cc
index 5aab132..daff129 100644
--- a/video/buffered_frame_decryptor.cc
+++ b/video/buffered_frame_decryptor.cc
@@ -73,7 +73,7 @@
   size_t bytes_written = 0;
   if (frame_decryptor_->Decrypt(
           cricket::MEDIA_TYPE_VIDEO, /*csrcs=*/{},
-          /*additional_data=*/nullptr, encrypted_frame_bitstream,
+          descriptor->GetByteRepresentation(), encrypted_frame_bitstream,
           inline_decrypted_bitstream, &bytes_written) != 0) {
     // Only stash frames if we have never decrypted a frame before.
     return first_frame_decrypted_ ? FrameDecision::kDrop