Add a libfuzzer for RtpHeaderParser.

webrtc/modules/rtp_rtcp/source/rtp_sender.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.
  */
 
@@ skipping 268 matching lines @@
       return rtp_header_extension_map_.RegisterInactive(type, id);
     case kRtpExtensionPlayoutDelay:
       playout_delay_active_ = false;
       return rtp_header_extension_map_.RegisterInactive(type, id);
     case kRtpExtensionTransmissionTimeOffset:
     case kRtpExtensionAbsoluteSendTime:
     case kRtpExtensionAudioLevel:
     case kRtpExtensionTransportSequenceNumber:
       return rtp_header_extension_map_.Register(type, id);
     case kRtpExtensionNone:
+    case kRtpExtensionNumberOfExtensions:
       LOG(LS_ERROR) << "Invalid RTP extension type for registration";
       return -1;
   }
   return -1;
 }
 
 bool RTPSender::IsRtpHeaderExtensionRegistered(RTPExtensionType type) {
   rtc::CritScope lock(&send_critsect_);
   return rtp_header_extension_map_.IsRegistered(type);
 }
@@ skipping 1697 matching lines @@
   rtc::CritScope lock(&send_critsect_);
 
   RtpState state;
   state.sequence_number = sequence_number_rtx_;
   state.start_timestamp = start_timestamp_;
 
   return state;
 }
 
 }  // namespace webrtc