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/call/call_perf_tests.cc b/call/call_perf_tests.cc
index 321f69c..5da1fae 100644
--- a/call/call_perf_tests.cc
+++ b/call/call_perf_tests.cc
@@ -27,7 +27,6 @@
 #include "modules/audio_coding/include/audio_coding_module.h"
 #include "modules/audio_device/include/test_audio_device.h"
 #include "modules/audio_mixer/audio_mixer_impl.h"
-#include "modules/rtp_rtcp/include/rtp_header_parser.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/thread_annotations.h"
 #include "system_wrappers/include/metrics.h"
@@ -41,6 +40,7 @@
 #include "test/frame_generator_capturer.h"
 #include "test/gtest.h"
 #include "test/null_transport.h"
+#include "test/rtp_header_parser.h"
 #include "test/rtp_rtcp_observer.h"
 #include "test/single_threaded_task_queue.h"
 #include "test/testsupport/file_utils.h"