Removes initial window field trial.

Bug: webrtc:9718
Change-Id: Ia1cc352bde1d8994cce7eb7e3bdcbc04e03fd718
Reviewed-on: https://webrtc-review.googlesource.com/c/104041
Reviewed-by: Christoffer Rodbro <crodbro@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25025}

modules/congestion_controller/goog_cc/goog_cc_network_control.cc

@@ -114,15 +114,6 @@ int64_t GetBpsOrDefault(const absl::optional<DataRate>& rate,
 
 }  // namespace
 
-InitialDataWindowConfig::InitialDataWindowConfig()
-    : size("size", DataSize::Infinity()), exit_rate_factor("rate", 1.0) {
-  std::string trial_string =
-      field_trial::FindFullName("WebRTC-Bwe-InitialDataWindow");
-  ParseFieldTrial({&size, &exit_rate_factor}, trial_string);
-}
-InitialDataWindowConfig::InitialDataWindowConfig(
-    const InitialDataWindowConfig&) = default;
-InitialDataWindowConfig::~InitialDataWindowConfig() = default;
 
 GoogCcNetworkController::GoogCcNetworkController(RtcEventLog* event_log,
                                                  NetworkControllerConfig config,
@@ -137,7 +128,6 @@ GoogCcNetworkController::GoogCcNetworkController(RtcEventLog* event_log,
       acknowledged_bitrate_estimator_(
           absl::make_unique<AcknowledgedBitrateEstimator>()),
       initial_config_(config),
-      initial_data_window_(InitialDataWindowConfig()),
       last_bandwidth_(*config.constraints.starting_rate),
       pacing_factor_(config.stream_based_config.pacing_factor.value_or(
           kDefaultPaceMultiplier)),
@@ -259,15 +249,7 @@ NetworkControlUpdate GoogCcNetworkController::OnSentPacket(
     SentPacket sent_packet) {
   alr_detector_->OnBytesSent(sent_packet.size.bytes(),
                              sent_packet.send_time.ms());
-  if (initial_state_ == InitialState::kWaitingForEstimate &&
+  return NetworkControlUpdate();
-      sent_packet.data_in_flight > initial_data_window_.size) {
-    initial_state_ = InitialState::kWindowFullWaitingForEstimate;
-    NetworkControlUpdate update;
-    MaybeTriggerOnNetworkChanged(&update, sent_packet.send_time);
-    return update;
-  } else {
-    return NetworkControlUpdate();
-  }
 }
 
 NetworkControlUpdate GoogCcNetworkController::OnStreamsConfig(
@@ -422,13 +404,6 @@ NetworkControlUpdate GoogCcNetworkController::OnTransportPacketsFeedback(
       received_feedback_vector, acknowledged_bitrate,
       report.feedback_time.ms());
 
-  if (acknowledged_bitrate || result.probe) {
-    if (initial_state_ == InitialState::kWindowFullWaitingForEstimate)
-      delay_based_bwe_->SetStartBitrate(result.target_bitrate_bps *
-                                        initial_data_window_.exit_rate_factor);
-    initial_state_ = InitialState::kReceivedEstimate;
-  }
-
   NetworkControlUpdate update;
   if (result.updated) {
     if (result.probe) {
@@ -503,9 +478,6 @@ void GoogCcNetworkController::MaybeTriggerOnNetworkChanged(
   estimated_bitrate_bps = std::max<int32_t>(
       estimated_bitrate_bps, bandwidth_estimation_->GetMinBitrate());
 
-  if (initial_state_ == InitialState::kWindowFullWaitingForEstimate)
-    estimated_bitrate_bps = bandwidth_estimation_->GetMinBitrate();
-
   BWE_TEST_LOGGING_PLOT(1, "fraction_loss_%", at_time.ms(),
                         (fraction_loss * 100) / 256);
   BWE_TEST_LOGGING_PLOT(1, "rtt_ms", at_time.ms(), rtt_ms);

modules/congestion_controller/goog_cc/goog_cc_network_control.h

@@ -25,18 +25,9 @@
 #include "modules/congestion_controller/goog_cc/delay_based_bwe.h"
 #include "modules/congestion_controller/goog_cc/probe_controller.h"
 #include "rtc_base/constructormagic.h"
-#include "rtc_base/experiments/field_trial_parser.h"
-#include "rtc_base/experiments/field_trial_units.h"
 
 namespace webrtc {
 
-struct InitialDataWindowConfig {
-  InitialDataWindowConfig();
-  InitialDataWindowConfig(const InitialDataWindowConfig&);
-  ~InitialDataWindowConfig();
-  FieldTrialParameter<DataSize> size;
-  FieldTrialParameter<double> exit_rate_factor;
-};
 
 class GoogCcNetworkController : public NetworkControllerInterface {
  public:
@@ -63,11 +54,6 @@ class GoogCcNetworkController : public NetworkControllerInterface {
 
  private:
   friend class GoogCcStatePrinter;
-  enum class InitialState {
-    kWaitingForEstimate,
-    kWindowFullWaitingForEstimate,
-    kReceivedEstimate
-  };
   std::vector<ProbeClusterConfig> UpdateBitrateConstraints(
       TargetRateConstraints constraints,
       absl::optional<DataRate> starting_rate);
@@ -87,9 +73,6 @@ class GoogCcNetworkController : public NetworkControllerInterface {
 
   absl::optional<NetworkControllerConfig> initial_config_;
 
-  const InitialDataWindowConfig initial_data_window_;
-  InitialState initial_state_ = InitialState::kWaitingForEstimate;
-
   Timestamp next_loss_update_ = Timestamp::MinusInfinity();
   int lost_packets_since_last_loss_update_ = 0;
   int expected_packets_since_last_loss_update_ = 0;