Make the RtpHeaderParserImpl available to tests and tools only.

There are a few reasons for making this test only:
* The code is only used by tests and utilities.
* The pure interface has only a single implementation so an interface isn't really needed.
  (a followup change could remove it altogether)
* The implementation always incorporates locking regardless of how the class gets used.
  See e.g. previous use in the Packet class.
* The implementation is a layer on top of RtpUtility::RtpHeaderParser which is
  sufficient for most production cases.

Change-Id: Ide6d50567cf8ae5127a2eb04cceeb10cf317ec36
Bug: none
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/150658
Commit-Queue: Tommi <tommi@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29010}
diff --git a/modules/audio_coding/neteq/tools/packet.cc b/modules/audio_coding/neteq/tools/packet.cc
index 4e2102d..6ed6f98 100644
--- a/modules/audio_coding/neteq/tools/packet.cc
+++ b/modules/audio_coding/neteq/tools/packet.cc
@@ -14,81 +14,53 @@
 
 #include <memory>
 
-#include "modules/rtp_rtcp/include/rtp_header_parser.h"
+#include "modules/rtp_rtcp/source/rtp_utility.h"
 #include "rtc_base/checks.h"
 
 namespace webrtc {
 namespace test {
 
-Packet::Packet(uint8_t* packet_memory,
-               size_t allocated_bytes,
-               double time_ms,
-               const RtpHeaderParser& parser)
-    : payload_memory_(packet_memory),
-      payload_(NULL),
-      packet_length_bytes_(allocated_bytes),
-      payload_length_bytes_(0),
-      virtual_packet_length_bytes_(allocated_bytes),
-      virtual_payload_length_bytes_(0),
-      time_ms_(time_ms) {
-  valid_header_ = ParseHeader(parser);
-}
+using webrtc::RtpUtility::RtpHeaderParser;
 
 Packet::Packet(uint8_t* packet_memory,
                size_t allocated_bytes,
                size_t virtual_packet_length_bytes,
                double time_ms,
-               const RtpHeaderParser& parser)
+               const RtpUtility::RtpHeaderParser& parser,
+               const RtpHeaderExtensionMap* extension_map /*= nullptr*/)
     : payload_memory_(packet_memory),
-      payload_(NULL),
       packet_length_bytes_(allocated_bytes),
-      payload_length_bytes_(0),
       virtual_packet_length_bytes_(virtual_packet_length_bytes),
       virtual_payload_length_bytes_(0),
-      time_ms_(time_ms) {
-  valid_header_ = ParseHeader(parser);
-}
+      time_ms_(time_ms),
+      valid_header_(ParseHeader(parser, extension_map)) {}
 
 Packet::Packet(const RTPHeader& header,
                size_t virtual_packet_length_bytes,
                size_t virtual_payload_length_bytes,
                double time_ms)
     : header_(header),
-      payload_memory_(),
-      payload_(NULL),
-      packet_length_bytes_(0),
-      payload_length_bytes_(0),
       virtual_packet_length_bytes_(virtual_packet_length_bytes),
       virtual_payload_length_bytes_(virtual_payload_length_bytes),
       time_ms_(time_ms),
       valid_header_(true) {}
 
 Packet::Packet(uint8_t* packet_memory, size_t allocated_bytes, double time_ms)
-    : payload_memory_(packet_memory),
-      payload_(NULL),
-      packet_length_bytes_(allocated_bytes),
-      payload_length_bytes_(0),
-      virtual_packet_length_bytes_(allocated_bytes),
-      virtual_payload_length_bytes_(0),
-      time_ms_(time_ms) {
-  std::unique_ptr<RtpHeaderParser> parser(RtpHeaderParser::Create());
-  valid_header_ = ParseHeader(*parser);
-}
+    : Packet(packet_memory,
+             allocated_bytes,
+             allocated_bytes,
+             time_ms,
+             RtpUtility::RtpHeaderParser(packet_memory, allocated_bytes)) {}
 
 Packet::Packet(uint8_t* packet_memory,
                size_t allocated_bytes,
                size_t virtual_packet_length_bytes,
                double time_ms)
-    : payload_memory_(packet_memory),
-      payload_(NULL),
-      packet_length_bytes_(allocated_bytes),
-      payload_length_bytes_(0),
-      virtual_packet_length_bytes_(virtual_packet_length_bytes),
-      virtual_payload_length_bytes_(0),
-      time_ms_(time_ms) {
-  std::unique_ptr<RtpHeaderParser> parser(RtpHeaderParser::Create());
-  valid_header_ = ParseHeader(*parser);
-}
+    : Packet(packet_memory,
+             allocated_bytes,
+             virtual_packet_length_bytes,
+             time_ms,
+             RtpUtility::RtpHeaderParser(packet_memory, allocated_bytes)) {}
 
 Packet::~Packet() = default;
 
@@ -139,9 +111,10 @@
   }
 }
 
-bool Packet::ParseHeader(const RtpHeaderParser& parser) {
-  bool valid_header = parser.Parse(
-      payload_memory_.get(), static_cast<int>(packet_length_bytes_), &header_);
+bool Packet::ParseHeader(const RtpHeaderParser& parser,
+                         const RtpHeaderExtensionMap* extension_map) {
+  bool valid_header = parser.Parse(&header_, extension_map);
+
   // Special case for dummy packets that have padding marked in the RTP header.
   // This causes the RTP header parser to report failure, but is fine in this
   // context.