Revert "Adds trial to use correct overhead calculation in pacer."

This reverts commit 71a77c4b3b314a5e3b4e6b2f12d4886cff1b60d7.

Reason for revert: https://webrtc-review.googlesource.com/c/src/+/167524 needs to be reverted and this CL causes a merge conflict.

Original change's description:
> Adds trial to use correct overhead calculation in pacer.
> 
> Bug: webrtc:9883
> Change-Id: I1f25a235468678bf823ee1399ba31d94acf33be9
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/166534
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Commit-Queue: Sebastian Jansson <srte@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#30399}

TBR=sprang@webrtc.org,srte@webrtc.org

Change-Id: I7d3efa29f70aa0363311766980acae6d88bbcaaa
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9883
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/167880
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30409}
diff --git a/call/rtp_transport_controller_send.cc b/call/rtp_transport_controller_send.cc
index 20f3a99..c2946ad 100644
--- a/call/rtp_transport_controller_send.cc
+++ b/call/rtp_transport_controller_send.cc
@@ -421,9 +421,6 @@
     return;
   }
 
-  pacer()->SetTransportOverhead(
-      DataSize::bytes(transport_overhead_bytes_per_packet));
-
   // TODO(holmer): Call AudioRtpSenders when they have been moved to
   // RtpTransportControllerSend.
   for (auto& rtp_video_sender : video_rtp_senders_) {
diff --git a/modules/pacing/paced_sender.cc b/modules/pacing/paced_sender.cc
index 3646952..6dc47b6 100644
--- a/modules/pacing/paced_sender.cc
+++ b/modules/pacing/paced_sender.cc
@@ -131,11 +131,6 @@
   pacing_controller_.SetIncludeOverhead();
 }
 
-void PacedSender::SetTransportOverhead(DataSize overhead_per_packet) {
-  rtc::CritScope cs(&critsect_);
-  pacing_controller_.SetTransportOverhead(overhead_per_packet);
-}
-
 TimeDelta PacedSender::ExpectedQueueTime() const {
   rtc::CritScope cs(&critsect_);
   return pacing_controller_.ExpectedQueueTime();
diff --git a/modules/pacing/paced_sender.h b/modules/pacing/paced_sender.h
index 16137df..3691308 100644
--- a/modules/pacing/paced_sender.h
+++ b/modules/pacing/paced_sender.h
@@ -98,7 +98,6 @@
   void SetAccountForAudioPackets(bool account_for_audio) override;
 
   void SetIncludeOverhead() override;
-  void SetTransportOverhead(DataSize overhead_per_packet) override;
 
   // Returns the time since the oldest queued packet was enqueued.
   TimeDelta OldestPacketWaitTime() const override;
diff --git a/modules/pacing/pacing_controller.cc b/modules/pacing/pacing_controller.cc
index f2b2149..09b7630 100644
--- a/modules/pacing/pacing_controller.cc
+++ b/modules/pacing/pacing_controller.cc
@@ -99,10 +99,7 @@
       pace_audio_(IsEnabled(*field_trials_, "WebRTC-Pacer-BlockAudio")),
       small_first_probe_packet_(
           IsEnabled(*field_trials_, "WebRTC-Pacer-SmallFirstProbePacket")),
-      ignore_transport_overhead_(
-          !IsDisabled(*field_trials_, "WebRTC-Pacer-IgnoreTransportOverhead")),
       min_packet_limit_(kDefaultMinPacketLimit),
-      transport_overhead_per_packet_(DataSize::Zero()),
       last_timestamp_(clock_->CurrentTime()),
       paused_(false),
       media_budget_(0),
@@ -233,13 +230,6 @@
   packet_queue_.SetIncludeOverhead();
 }
 
-void PacingController::SetTransportOverhead(DataSize overhead_per_packet) {
-  if (ignore_transport_overhead_)
-    return;
-  transport_overhead_per_packet_ = overhead_per_packet;
-  packet_queue_.SetTransportOverhead(overhead_per_packet);
-}
-
 TimeDelta PacingController::ExpectedQueueTime() const {
   RTC_DCHECK_GT(pacing_bitrate_, DataRate::Zero());
   return TimeDelta::ms(
@@ -531,13 +521,10 @@
     RTC_DCHECK(rtp_packet);
     RTC_DCHECK(rtp_packet->packet_type().has_value());
     const RtpPacketToSend::Type packet_type = *rtp_packet->packet_type();
-    DataSize packet_size = DataSize::bytes(rtp_packet->payload_size() +
-                                           rtp_packet->padding_size());
-
-    if (include_overhead_) {
-      packet_size += DataSize::bytes(rtp_packet->headers_size()) +
-                     transport_overhead_per_packet_;
-    }
+    const DataSize packet_size =
+        DataSize::bytes(include_overhead_ ? rtp_packet->size()
+                                          : rtp_packet->payload_size() +
+                                                rtp_packet->padding_size());
     packet_sender_->SendRtpPacket(std::move(rtp_packet), pacing_info);
 
     data_sent += packet_size;
diff --git a/modules/pacing/pacing_controller.h b/modules/pacing/pacing_controller.h
index c1b3942..fb4d9d3 100644
--- a/modules/pacing/pacing_controller.h
+++ b/modules/pacing/pacing_controller.h
@@ -109,8 +109,6 @@
   void SetAccountForAudioPackets(bool account_for_audio);
   void SetIncludeOverhead();
 
-  void SetTransportOverhead(DataSize overhead_per_packet);
-
   // Returns the time since the oldest queued packet was enqueued.
   TimeDelta OldestPacketWaitTime() const;
 
@@ -179,12 +177,9 @@
   const bool send_padding_if_silent_;
   const bool pace_audio_;
   const bool small_first_probe_packet_;
-  const bool ignore_transport_overhead_;
 
   TimeDelta min_packet_limit_;
 
-  DataSize transport_overhead_per_packet_;
-
   // TODO(webrtc:9716): Remove this when we are certain clocks are monotonic.
   // The last millisecond timestamp returned by |clock_|.
   mutable Timestamp last_timestamp_;
diff --git a/modules/pacing/round_robin_packet_queue.cc b/modules/pacing/round_robin_packet_queue.cc
index 32f288c..754ff58 100644
--- a/modules/pacing/round_robin_packet_queue.cc
+++ b/modules/pacing/round_robin_packet_queue.cc
@@ -73,6 +73,12 @@
   return enqueue_order_;
 }
 
+DataSize RoundRobinPacketQueue::QueuedPacket::Size(bool count_overhead) const {
+  return DataSize::bytes(count_overhead ? owned_packet_->size()
+                                        : owned_packet_->payload_size() +
+                                              owned_packet_->padding_size());
+}
+
 RtpPacketToSend* RoundRobinPacketQueue::QueuedPacket::RtpPacket() const {
   return owned_packet_;
 }
@@ -111,8 +117,7 @@
 RoundRobinPacketQueue::RoundRobinPacketQueue(
     Timestamp start_time,
     const WebRtcKeyValueConfig* field_trials)
-    : transport_overhead_per_packet_(DataSize::Zero()),
-      time_last_updated_(start_time),
+    : time_last_updated_(start_time),
       paused_(false),
       size_packets_(0),
       size_(DataSize::Zero()),
@@ -162,13 +167,7 @@
   // case a "budget" will be built up for the stream sending at the lower
   // rate. To avoid building a too large budget we limit |bytes| to be within
   // kMaxLeading bytes of the stream that has sent the most amount of bytes.
-  DataSize packet_size =
-      DataSize::bytes(queued_packet.RtpPacket()->payload_size() +
-                      queued_packet.RtpPacket()->padding_size());
-  if (include_overhead_) {
-    packet_size += DataSize::bytes(queued_packet.RtpPacket()->headers_size()) +
-                   transport_overhead_per_packet_;
-  }
+  DataSize packet_size = queued_packet.Size(include_overhead_);
   stream->size =
       std::max(stream->size + packet_size, max_size_ - kMaxLeadingSize);
   max_size_ = std::max(max_size_, stream->size);
@@ -251,18 +250,14 @@
 void RoundRobinPacketQueue::SetIncludeOverhead() {
   include_overhead_ = true;
   // We need to update the size to reflect overhead for existing packets.
+  size_ = DataSize::Zero();
   for (const auto& stream : streams_) {
     for (const QueuedPacket& packet : stream.second.packet_queue) {
-      size_ += DataSize::bytes(packet.RtpPacket()->headers_size()) +
-               transport_overhead_per_packet_;
+      size_ += packet.Size(include_overhead_);
     }
   }
 }
 
-void RoundRobinPacketQueue::SetTransportOverhead(DataSize overhead_per_packet) {
-  transport_overhead_per_packet_ = overhead_per_packet;
-}
-
 TimeDelta RoundRobinPacketQueue::AverageQueueTime() const {
   if (Empty())
     return TimeDelta::Zero();
@@ -304,12 +299,7 @@
   packet.SubtractPauseTime(pause_time_sum_);
 
   size_packets_ += 1;
-  size_ += DataSize::bytes(packet.RtpPacket()->payload_size() +
-                           packet.RtpPacket()->padding_size());
-  if (include_overhead_) {
-    size_ += DataSize::bytes(packet.RtpPacket()->headers_size()) +
-             transport_overhead_per_packet_;
-  }
+  size_ += packet.Size(include_overhead_);
 
   stream->packet_queue.push(packet);
 }
diff --git a/modules/pacing/round_robin_packet_queue.h b/modules/pacing/round_robin_packet_queue.h
index 225e137..d0a2f7c 100644
--- a/modules/pacing/round_robin_packet_queue.h
+++ b/modules/pacing/round_robin_packet_queue.h
@@ -53,7 +53,6 @@
   void UpdateQueueTime(Timestamp now);
   void SetPauseState(bool paused, Timestamp now);
   void SetIncludeOverhead();
-  void SetTransportOverhead(DataSize overhead_per_packet);
 
  private:
   struct QueuedPacket {
@@ -74,6 +73,7 @@
     Timestamp EnqueueTime() const;
     bool IsRetransmission() const;
     uint64_t EnqueueOrder() const;
+    DataSize Size(bool count_overhead) const;
     RtpPacketToSend* RtpPacket() const;
 
     std::multiset<Timestamp>::iterator EnqueueTimeIterator() const;
@@ -137,8 +137,6 @@
   // Just used to verify correctness.
   bool IsSsrcScheduled(uint32_t ssrc) const;
 
-  DataSize transport_overhead_per_packet_;
-
   Timestamp time_last_updated_;
 
   bool paused_;
diff --git a/modules/pacing/rtp_packet_pacer.h b/modules/pacing/rtp_packet_pacer.h
index d826edd..2f11c1f 100644
--- a/modules/pacing/rtp_packet_pacer.h
+++ b/modules/pacing/rtp_packet_pacer.h
@@ -65,7 +65,6 @@
   // at high priority.
   virtual void SetAccountForAudioPackets(bool account_for_audio) = 0;
   virtual void SetIncludeOverhead() = 0;
-  virtual void SetTransportOverhead(DataSize overhead_per_packet) = 0;
 };
 
 }  // namespace webrtc
diff --git a/modules/pacing/task_queue_paced_sender.cc b/modules/pacing/task_queue_paced_sender.cc
index 646af4e..54d2d84 100644
--- a/modules/pacing/task_queue_paced_sender.cc
+++ b/modules/pacing/task_queue_paced_sender.cc
@@ -143,13 +143,6 @@
   });
 }
 
-void TaskQueuePacedSender::SetTransportOverhead(DataSize overhead_per_packet) {
-  task_queue_.PostTask([this, overhead_per_packet]() {
-    RTC_DCHECK_RUN_ON(&task_queue_);
-    pacing_controller_.SetTransportOverhead(overhead_per_packet);
-  });
-}
-
 void TaskQueuePacedSender::SetQueueTimeLimit(TimeDelta limit) {
   task_queue_.PostTask([this, limit]() {
     RTC_DCHECK_RUN_ON(&task_queue_);
diff --git a/modules/pacing/task_queue_paced_sender.h b/modules/pacing/task_queue_paced_sender.h
index 8b47f5e..a50ffa2 100644
--- a/modules/pacing/task_queue_paced_sender.h
+++ b/modules/pacing/task_queue_paced_sender.h
@@ -80,8 +80,6 @@
   void SetAccountForAudioPackets(bool account_for_audio) override;
 
   void SetIncludeOverhead() override;
-  void SetTransportOverhead(DataSize overhead_per_packet) override;
-
   // Returns the time since the oldest queued packet was enqueued.
   TimeDelta OldestPacketWaitTime() const override;