Introduce helpers to RtpSender to propagate RtpPacketToSend.

webrtc/modules/rtp_rtcp/source/rtp_packet.h

 /*
  *  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.
  */
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_H_
@@ skipping 65 matching lines @@
   void SetSequenceNumber(uint16_t seq_no);
   void SetTimestamp(uint32_t timestamp);
   void SetSsrc(uint32_t ssrc);
 
   // Writes csrc list. Assumes:
   // a) There is enough room left in buffer.
   // b) Extension headers, payload or padding data has not already been added.
   void SetCsrcs(const std::vector<uint32_t>& csrcs);
 
   // Header extensions.
+  template <typename Extension>
+  bool HasExtension() const;
+
   template <typename Extension, typename... Values>
   bool GetExtension(Values...) const;
 
   template <typename Extension, typename... Values>
   bool SetExtension(Values...);
 
   template <typename Extension>
   bool ReserveExtension();
 
   // Reserve size_bytes for payload. Returns nullptr on failure.
@@ skipping 57 matching lines @@
   size_t payload_size_;
 
   uint8_t num_extensions_ = 0;
   ExtensionInfo extension_entries_[kMaxExtensionHeaders];
   uint16_t extensions_size_ = 0;  // Unaligned.
   rtc::CopyOnWriteBuffer buffer_;
 
   Packet() = delete;
 };
 
+template <typename Extension>
+bool Packet::HasExtension() const {
+  uint16_t offset = 0;
+  return FindExtension(Extension::kId, Extension::kValueSizeBytes, &offset);
+}
+
 template <typename Extension, typename... Values>
 bool Packet::GetExtension(Values... values) const {
   uint16_t offset = 0;
   if (!FindExtension(Extension::kId, Extension::kValueSizeBytes, &offset))
     return false;
   return Extension::Parse(data() + offset, values...);
 }
 
 template <typename Extension, typename... Values>
 bool Packet::SetExtension(Values... values) {
   uint16_t offset = 0;
   if (!AllocateExtension(Extension::kId, Extension::kValueSizeBytes, &offset))
     return false;
   return Extension::Write(WriteAt(offset), values...);
 }
 
 template <typename Extension>
 bool Packet::ReserveExtension() {
   uint16_t offset = 0;
   if (!AllocateExtension(Extension::kId, Extension::kValueSizeBytes, &offset))
     return false;
   memset(WriteAt(offset), 0, Extension::kValueSizeBytes);
   return true;
 }
 }  // namespace rtp
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_H_