Replace rtc::Optional with absl::optional

This is a no-op change because rtc::Optional is an alias to absl::optional

This CL generated by running script from modules with parameters
'pacing video_coding congestion_controller remote_bitrate_estimator':

find $@ -type f \( -name \*.h -o -name \*.cc \) \
-exec sed -i 's|rtc::Optional|absl::optional|g' {} \+ \
-exec sed -i 's|rtc::nullopt|absl::nullopt|g' {} \+ \
-exec sed -i 's|#include "api/optional.h"|#include "absl/types/optional.h"|' {} \+

find $@ -type f -name BUILD.gn \
-exec sed -r -i 's|"(../)*api:optional"|"//third_party/abseil-cpp/absl/types:optional"|' {} \+;

git cl format

Bug: webrtc:9078
Change-Id: I8ea501d7f1ee36e8d8cd3ed37e6b763c7fe29118
Reviewed-on: https://webrtc-review.googlesource.com/83900
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23640}

modules/video_coding/utility/moving_average.cc

@@ -23,13 +23,13 @@ void MovingAverage::AddSample(int sample) {
   sum_history_[count_ % sum_history_.size()] = sum_;
 }
 
-rtc::Optional<int> MovingAverage::GetAverage() const {
+absl::optional<int> MovingAverage::GetAverage() const {
   return GetAverage(size());
 }
 
-rtc::Optional<int> MovingAverage::GetAverage(size_t num_samples) const {
+absl::optional<int> MovingAverage::GetAverage(size_t num_samples) const {
   if (num_samples > size() || num_samples == 0)
-    return rtc::nullopt;
+    return absl::nullopt;
   int sum = sum_ - sum_history_[(count_ - num_samples) % sum_history_.size()];
   return sum / static_cast<int>(num_samples);
 }

modules/video_coding/utility/moving_average.h

@@ -13,7 +13,7 @@
 
 #include <vector>
 
-#include "api/optional.h"
+#include "absl/types/optional.h"
 
 namespace webrtc {
 class MovingAverage {
@@ -21,8 +21,8 @@ class MovingAverage {
   explicit MovingAverage(size_t s);
   ~MovingAverage();
   void AddSample(int sample);
-  rtc::Optional<int> GetAverage() const;
-  rtc::Optional<int> GetAverage(size_t num_samples) const;
+  absl::optional<int> GetAverage() const;
+  absl::optional<int> GetAverage(size_t num_samples) const;
   void Reset();
   size_t size() const;
 

modules/video_coding/utility/quality_scaler.cc

@@ -44,10 +44,10 @@ class QualityScaler::QpSmoother {
   explicit QpSmoother(float alpha)
       : alpha_(alpha), last_sample_ms_(rtc::TimeMillis()), smoother_(alpha) {}
 
-  rtc::Optional<int> GetAvg() const {
+  absl::optional<int> GetAvg() const {
     float value = smoother_.filtered();
     if (value == rtc::ExpFilter::kValueUndefined) {
-      return rtc::nullopt;
+      return absl::nullopt;
     }
     return static_cast<int>(value);
   }
@@ -182,7 +182,7 @@ void QualityScaler::CheckQp() {
   observed_enough_frames_ = true;
 
   // Check if we should scale down due to high frame drop.
-  const rtc::Optional<int> drop_rate =
+  const absl::optional<int> drop_rate =
       config_.use_all_drop_reasons ? framedrop_percent_all_.GetAverage()
                                    : framedrop_percent_media_opt_.GetAverage();
   if (drop_rate && *drop_rate >= kFramedropPercentThreshold) {
@@ -192,10 +192,10 @@ void QualityScaler::CheckQp() {
   }
 
   // Check if we should scale up or down based on QP.
-  const rtc::Optional<int> avg_qp_high = qp_smoother_high_
-                                             ? qp_smoother_high_->GetAvg()
-                                             : average_qp_.GetAverage();
-  const rtc::Optional<int> avg_qp_low =
+  const absl::optional<int> avg_qp_high = qp_smoother_high_
+                                              ? qp_smoother_high_->GetAvg()
+                                              : average_qp_.GetAverage();
+  const absl::optional<int> avg_qp_low =
       qp_smoother_low_ ? qp_smoother_low_->GetAvg() : average_qp_.GetAverage();
   if (avg_qp_high && avg_qp_low) {
     RTC_LOG(LS_INFO) << "Checking average QP " << *avg_qp_high << " ("

modules/video_coding/utility/quality_scaler.h

@@ -14,7 +14,7 @@
 #include <memory>
 #include <utility>
 
-#include "api/optional.h"
+#include "absl/types/optional.h"
 #include "api/video_codecs/video_encoder.h"
 #include "common_types.h"  // NOLINT(build/include)
 #include "modules/video_coding/utility/moving_average.h"