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/rtp_rtcp/BUILD.gn b/modules/rtp_rtcp/BUILD.gn
index 06ed9bd..24ed0d2 100644
--- a/modules/rtp_rtcp/BUILD.gn
+++ b/modules/rtp_rtcp/BUILD.gn
@@ -129,7 +129,6 @@
     "include/flexfec_sender.h",
     "include/receive_statistics.h",
     "include/remote_ntp_time_estimator.h",
-    "include/rtp_header_parser.h",
     "include/rtp_rtcp.h",
     "include/ulpfec_receiver.h",
     "source/absolute_capture_time_receiver.cc",
@@ -175,7 +174,6 @@
     "source/rtp_format_vp9.h",
     "source/rtp_header_extension_size.cc",
     "source/rtp_header_extension_size.h",
-    "source/rtp_header_parser.cc",
     "source/rtp_packet_history.cc",
     "source/rtp_packet_history.h",
     "source/rtp_rtcp_config.h",
diff --git a/modules/rtp_rtcp/include/rtp_header_parser.h b/modules/rtp_rtcp/include/rtp_header_parser.h
deleted file mode 100644
index 0afcb71..0000000
--- a/modules/rtp_rtcp/include/rtp_header_parser.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- *  Copyright (c) 2013 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 MODULES_RTP_RTCP_INCLUDE_RTP_HEADER_PARSER_H_
-#define MODULES_RTP_RTCP_INCLUDE_RTP_HEADER_PARSER_H_
-
-#include "api/rtp_parameters.h"
-#include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
-
-namespace webrtc {
-
-struct RTPHeader;
-
-class RtpHeaderParser {
- public:
-  static RtpHeaderParser* Create();
-  virtual ~RtpHeaderParser() {}
-
-  // Returns true if the packet is an RTCP packet, false otherwise.
-  static bool IsRtcp(const uint8_t* packet, size_t length);
-  static absl::optional<uint32_t> GetSsrc(const uint8_t* packet, size_t length);
-
-  // Parses the packet and stores the parsed packet in |header|. Returns true on
-  // success, false otherwise.
-  // This method is thread-safe in the sense that it can parse multiple packets
-  // at once.
-  virtual bool Parse(const uint8_t* packet,
-                     size_t length,
-                     RTPHeader* header) const = 0;
-
-  // Registers an RTP header extension and binds it to |id|.
-  virtual bool RegisterRtpHeaderExtension(RTPExtensionType type,
-                                          uint8_t id) = 0;
-
-  // Registers an RTP header extension.
-  virtual bool RegisterRtpHeaderExtension(RtpExtension extension) = 0;
-
-  // De-registers an RTP header extension.
-  virtual bool DeregisterRtpHeaderExtension(RTPExtensionType type) = 0;
-
-  // De-registers an RTP header extension.
-  virtual bool DeregisterRtpHeaderExtension(RtpExtension extension) = 0;
-};
-}  // namespace webrtc
-#endif  // MODULES_RTP_RTCP_INCLUDE_RTP_HEADER_PARSER_H_
diff --git a/modules/rtp_rtcp/source/rtp_header_parser.cc b/modules/rtp_rtcp/source/rtp_header_parser.cc
deleted file mode 100644
index 65431d1..0000000
--- a/modules/rtp_rtcp/source/rtp_header_parser.cc
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- *  Copyright (c) 2013 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.
- */
-#include "modules/rtp_rtcp/include/rtp_header_parser.h"
-
-#include <string.h>
-
-#include "modules/rtp_rtcp/include/rtp_header_extension_map.h"
-#include "modules/rtp_rtcp/source/rtp_utility.h"
-#include "rtc_base/critical_section.h"
-#include "rtc_base/thread_annotations.h"
-
-namespace webrtc {
-
-class RtpHeaderParserImpl : public RtpHeaderParser {
- public:
-  RtpHeaderParserImpl();
-  ~RtpHeaderParserImpl() override = default;
-
-  bool Parse(const uint8_t* packet,
-             size_t length,
-             RTPHeader* header) const override;
-
-  bool RegisterRtpHeaderExtension(RTPExtensionType type, uint8_t id) override;
-  bool RegisterRtpHeaderExtension(RtpExtension extension) override;
-
-  bool DeregisterRtpHeaderExtension(RTPExtensionType type) override;
-  bool DeregisterRtpHeaderExtension(RtpExtension extension) override;
-
- private:
-  rtc::CriticalSection critical_section_;
-  RtpHeaderExtensionMap rtp_header_extension_map_
-      RTC_GUARDED_BY(critical_section_);
-};
-
-RtpHeaderParser* RtpHeaderParser::Create() {
-  return new RtpHeaderParserImpl;
-}
-
-RtpHeaderParserImpl::RtpHeaderParserImpl() {}
-
-bool RtpHeaderParser::IsRtcp(const uint8_t* packet, size_t length) {
-  RtpUtility::RtpHeaderParser rtp_parser(packet, length);
-  return rtp_parser.RTCP();
-}
-
-absl::optional<uint32_t> RtpHeaderParser::GetSsrc(const uint8_t* packet,
-                                                  size_t length) {
-  RtpUtility::RtpHeaderParser rtp_parser(packet, length);
-  RTPHeader header;
-  if (rtp_parser.Parse(&header, nullptr)) {
-    return header.ssrc;
-  }
-  return absl::nullopt;
-}
-
-bool RtpHeaderParserImpl::Parse(const uint8_t* packet,
-                                size_t length,
-                                RTPHeader* header) const {
-  RtpUtility::RtpHeaderParser rtp_parser(packet, length);
-  *header = RTPHeader();
-
-  RtpHeaderExtensionMap map;
-  {
-    rtc::CritScope cs(&critical_section_);
-    map = rtp_header_extension_map_;
-  }
-
-  const bool valid_rtpheader = rtp_parser.Parse(header, &map);
-  if (!valid_rtpheader) {
-    return false;
-  }
-  return true;
-}
-bool RtpHeaderParserImpl::RegisterRtpHeaderExtension(RtpExtension extension) {
-  rtc::CritScope cs(&critical_section_);
-  return rtp_header_extension_map_.RegisterByUri(extension.id, extension.uri);
-}
-
-bool RtpHeaderParserImpl::RegisterRtpHeaderExtension(RTPExtensionType type,
-                                                     uint8_t id) {
-  rtc::CritScope cs(&critical_section_);
-  return rtp_header_extension_map_.RegisterByType(id, type);
-}
-
-bool RtpHeaderParserImpl::DeregisterRtpHeaderExtension(RtpExtension extension) {
-  rtc::CritScope cs(&critical_section_);
-  return rtp_header_extension_map_.Deregister(
-      rtp_header_extension_map_.GetType(extension.id));
-}
-
-bool RtpHeaderParserImpl::DeregisterRtpHeaderExtension(RTPExtensionType type) {
-  rtc::CritScope cs(&critical_section_);
-  return rtp_header_extension_map_.Deregister(type) == 0;
-}
-}  // namespace webrtc
diff --git a/modules/rtp_rtcp/source/rtp_rtcp_impl_unittest.cc b/modules/rtp_rtcp/source/rtp_rtcp_impl_unittest.cc
index e6f8db1..f55e4f8 100644
--- a/modules/rtp_rtcp/source/rtp_rtcp_impl_unittest.cc
+++ b/modules/rtp_rtcp/source/rtp_rtcp_impl_unittest.cc
@@ -17,7 +17,6 @@
 #include "absl/memory/memory.h"
 #include "api/transport/field_trial_based_config.h"
 #include "api/video_codecs/video_codec.h"
-#include "modules/rtp_rtcp/include/rtp_header_parser.h"
 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "modules/rtp_rtcp/source/playout_delay_oracle.h"
 #include "modules/rtp_rtcp/source/rtcp_packet.h"
@@ -28,6 +27,7 @@
 #include "test/gmock.h"
 #include "test/gtest.h"
 #include "test/rtcp_packet_parser.h"
+#include "test/rtp_header_parser.h"
 
 using ::testing::_;
 using ::testing::ElementsAre;
@@ -72,7 +72,7 @@
                size_t len,
                const PacketOptions& options) override {
     RTPHeader header;
-    std::unique_ptr<RtpHeaderParser> parser(RtpHeaderParser::Create());
+    std::unique_ptr<RtpHeaderParser> parser(RtpHeaderParser::CreateForTest());
     EXPECT_TRUE(parser->Parse(static_cast<const uint8_t*>(data), len, &header));
     ++rtp_packets_sent_;
     last_rtp_header_ = header;
diff --git a/modules/rtp_rtcp/source/rtp_sender_unittest.cc b/modules/rtp_rtcp/source/rtp_sender_unittest.cc
index 125a0b8..ad501df 100644
--- a/modules/rtp_rtcp/source/rtp_sender_unittest.cc
+++ b/modules/rtp_rtcp/source/rtp_sender_unittest.cc
@@ -21,7 +21,6 @@
 #include "logging/rtc_event_log/mock/mock_rtc_event_log.h"
 #include "modules/rtp_rtcp/include/rtp_cvo.h"
 #include "modules/rtp_rtcp/include/rtp_header_extension_map.h"
-#include "modules/rtp_rtcp/include/rtp_header_parser.h"
 #include "modules/rtp_rtcp/include/rtp_packet_sender.h"
 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
@@ -39,6 +38,7 @@
 #include "test/gmock.h"
 #include "test/gtest.h"
 #include "test/mock_transport.h"
+#include "test/rtp_header_parser.h"
 
 namespace webrtc {
 
diff --git a/modules/rtp_rtcp/source/ulpfec_receiver_unittest.cc b/modules/rtp_rtcp/source/ulpfec_receiver_unittest.cc
index cd1798b..32f3bbb 100644
--- a/modules/rtp_rtcp/source/ulpfec_receiver_unittest.cc
+++ b/modules/rtp_rtcp/source/ulpfec_receiver_unittest.cc
@@ -15,7 +15,6 @@
 #include <list>
 #include <memory>
 
-#include "modules/rtp_rtcp/include/rtp_header_parser.h"
 #include "modules/rtp_rtcp/mocks/mock_recovered_packet_receiver.h"
 #include "modules/rtp_rtcp/mocks/mock_rtp_rtcp.h"
 #include "modules/rtp_rtcp/source/byte_io.h"
@@ -23,6 +22,7 @@
 #include "modules/rtp_rtcp/source/forward_error_correction.h"
 #include "test/gmock.h"
 #include "test/gtest.h"
+#include "test/rtp_header_parser.h"
 
 namespace webrtc {
 
@@ -177,7 +177,7 @@
                                                  size_t length,
                                                  uint8_t ulpfec_payload_type) {
   RTPHeader header;
-  std::unique_ptr<RtpHeaderParser> parser(RtpHeaderParser::Create());
+  std::unique_ptr<RtpHeaderParser> parser(RtpHeaderParser::CreateForTest());
   ASSERT_TRUE(parser->Parse(data, length, &header));
 
   NullRecoveredPacketReceiver null_callback;