[Unwrap] Prepare SequenceNumberUnwrapper for migrations

This is in prep for the migration of all unwrappers to
SequenceNumberUnwrapper as a standard implementation.

This moves the SeqNumUnwapper to its own header and adds 2 methods to
SeqNumUnwrapper which are defined by other unwrappers:
* PeekUnwrap
* Reset

It also adds two implementations for RtpTimestamps and
RtpSequenceNumbers.

Bug: webrtc:13982
Change-Id: I5baefb2de1db92fe1bb600760bd63b71e9310eb5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/288742
Commit-Queue: Evan Shrubsole <eshr@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Auto-Submit: Evan Shrubsole <eshr@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39030}
diff --git a/modules/video_coding/codecs/av1/libaom_av1_encoder.cc b/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
index 4d8786c..2713171 100644
--- a/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
+++ b/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
@@ -33,7 +33,7 @@
 #include "modules/video_coding/svc/scalable_video_controller_no_layering.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/numerics/sequence_number_util.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
 #include "third_party/libaom/source/libaom/aom/aom_codec.h"
 #include "third_party/libaom/source/libaom/aom/aom_encoder.h"
 #include "third_party/libaom/source/libaom/aom/aomcx.h"
diff --git a/modules/video_coding/h264_packet_buffer.h b/modules/video_coding/h264_packet_buffer.h
index 1671fdd..a72c240 100644
--- a/modules/video_coding/h264_packet_buffer.h
+++ b/modules/video_coding/h264_packet_buffer.h
@@ -18,7 +18,7 @@
 #include "absl/base/attributes.h"
 #include "absl/types/optional.h"
 #include "modules/video_coding/packet_buffer.h"
-#include "rtc_base/numerics/sequence_number_util.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
 
 namespace webrtc {
 
diff --git a/modules/video_coding/packet_buffer_unittest.cc b/modules/video_coding/packet_buffer_unittest.cc
index 49afa14..b147977 100644
--- a/modules/video_coding/packet_buffer_unittest.cc
+++ b/modules/video_coding/packet_buffer_unittest.cc
@@ -18,6 +18,7 @@
 #include "api/array_view.h"
 #include "common_video/h264/h264_common.h"
 #include "modules/video_coding/frame_object.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
 #include "rtc_base/random.h"
 #include "test/field_trial.h"
 #include "test/gmock.h"
diff --git a/modules/video_coding/rtp_frame_id_only_ref_finder.h b/modules/video_coding/rtp_frame_id_only_ref_finder.h
index 1df4870..5c0bdc8 100644
--- a/modules/video_coding/rtp_frame_id_only_ref_finder.h
+++ b/modules/video_coding/rtp_frame_id_only_ref_finder.h
@@ -16,7 +16,7 @@
 #include "absl/container/inlined_vector.h"
 #include "modules/video_coding/frame_object.h"
 #include "modules/video_coding/rtp_frame_reference_finder.h"
-#include "rtc_base/numerics/sequence_number_util.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
 
 namespace webrtc {
 
diff --git a/modules/video_coding/rtp_seq_num_only_ref_finder.h b/modules/video_coding/rtp_seq_num_only_ref_finder.h
index ef3c022..c05655b 100644
--- a/modules/video_coding/rtp_seq_num_only_ref_finder.h
+++ b/modules/video_coding/rtp_seq_num_only_ref_finder.h
@@ -20,7 +20,7 @@
 #include "absl/container/inlined_vector.h"
 #include "modules/video_coding/frame_object.h"
 #include "modules/video_coding/rtp_frame_reference_finder.h"
-#include "rtc_base/numerics/sequence_number_util.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
 
 namespace webrtc {
 
diff --git a/modules/video_coding/rtp_vp8_ref_finder.h b/modules/video_coding/rtp_vp8_ref_finder.h
index 1ae45cd..26df658 100644
--- a/modules/video_coding/rtp_vp8_ref_finder.h
+++ b/modules/video_coding/rtp_vp8_ref_finder.h
@@ -19,7 +19,7 @@
 #include "absl/container/inlined_vector.h"
 #include "modules/video_coding/frame_object.h"
 #include "modules/video_coding/rtp_frame_reference_finder.h"
-#include "rtc_base/numerics/sequence_number_util.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
 
 namespace webrtc {
 
diff --git a/modules/video_coding/rtp_vp9_ref_finder.h b/modules/video_coding/rtp_vp9_ref_finder.h
index 2971f68..ea5e319 100644
--- a/modules/video_coding/rtp_vp9_ref_finder.h
+++ b/modules/video_coding/rtp_vp9_ref_finder.h
@@ -19,7 +19,7 @@
 #include "absl/container/inlined_vector.h"
 #include "modules/video_coding/frame_object.h"
 #include "modules/video_coding/rtp_frame_reference_finder.h"
-#include "rtc_base/numerics/sequence_number_util.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
 
 namespace webrtc {