FEC protect H264 delta frames as well.

webrtc/modules/rtp_rtcp/source/rtp_format_vp8.cc

 /*
  *  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 216 matching lines @@
   return true;
 }
 
 ProtectionType RtpPacketizerVp8::GetProtectionType() {
   bool protect =
       hdr_info_.temporalIdx == 0 || hdr_info_.temporalIdx == kNoTemporalIdx;
   return protect ? kProtectedPacket : kUnprotectedPacket;
 }
 
 StorageType RtpPacketizerVp8::GetStorageType(uint32_t retransmission_settings) {
-  StorageType storage = kAllowRetransmission;
   if (hdr_info_.temporalIdx == 0 &&
       !(retransmission_settings & kRetransmitBaseLayer)) {
-    storage = kDontRetransmit;
-  } else if (hdr_info_.temporalIdx != kNoTemporalIdx &&
+    return kDontRetransmit;
+  }
+  if (hdr_info_.temporalIdx != kNoTemporalIdx &&
              hdr_info_.temporalIdx > 0 &&
              !(retransmission_settings & kRetransmitHigherLayers)) {
-    storage = kDontRetransmit;
+    return kDontRetransmit;
   }
-  return storage;
+  return kAllowRetransmission;
 }
 
 std::string RtpPacketizerVp8::ToString() {
   return "RtpPacketizerVp8";
 }
 
 size_t RtpPacketizerVp8::CalcNextSize(size_t max_payload_len,
                                       size_t remaining_bytes,
                                       bool split_payload) const {
   if (max_payload_len == 0 || remaining_bytes == 0) {
@@ skipping 477 matching lines @@
   if (ParseVP8FrameSize(parsed_payload, payload_data, payload_data_length) !=
       0) {
     return false;
   }
 
   parsed_payload->payload = payload_data;
   parsed_payload->payload_length = payload_data_length;
   return true;
 }
 }  // namespace webrtc