Replace rtc::Optional with absl::optional in modules/audio processing

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

This CL generated by running script with parameter 'modules/audio_processing'

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: Id29f8de59dba704787c2c38a3d05c60827c181b0
Reviewed-on: https://webrtc-review.googlesource.com/83982
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23653}
diff --git a/modules/audio_processing/include/audio_processing_statistics.h b/modules/audio_processing/include/audio_processing_statistics.h
index 05c5905..237d23c 100644
--- a/modules/audio_processing/include/audio_processing_statistics.h
+++ b/modules/audio_processing/include/audio_processing_statistics.h
@@ -11,7 +11,7 @@
 #ifndef MODULES_AUDIO_PROCESSING_INCLUDE_AUDIO_PROCESSING_STATISTICS_H_
 #define MODULES_AUDIO_PROCESSING_INCLUDE_AUDIO_PROCESSING_STATISTICS_H_
 
-#include "api/optional.h"
+#include "absl/types/optional.h"
 
 namespace webrtc {
 // This version of the stats uses Optionals, it will replace the regular
@@ -23,12 +23,12 @@
 
   // AEC Statistics.
   // ERL = 10log_10(P_far / P_echo)
-  rtc::Optional<double> echo_return_loss;
+  absl::optional<double> echo_return_loss;
   // ERLE = 10log_10(P_echo / P_out)
-  rtc::Optional<double> echo_return_loss_enhancement;
+  absl::optional<double> echo_return_loss_enhancement;
   // Fraction of time that the AEC linear filter is divergent, in a 1-second
   // non-overlapped aggregation window.
-  rtc::Optional<double> divergent_filter_fraction;
+  absl::optional<double> divergent_filter_fraction;
 
   // The delay metrics consists of the delay median and standard deviation. It
   // also consists of the fraction of delay estimates that can make the echo
@@ -37,18 +37,18 @@
   // second. Note that if there are several clients pulling metrics from
   // |GetStatistics()| during a session the first call from any of them will
   // change to one second aggregation window for all.
-  rtc::Optional<int32_t> delay_median_ms;
-  rtc::Optional<int32_t> delay_standard_deviation_ms;
+  absl::optional<int32_t> delay_median_ms;
+  absl::optional<int32_t> delay_standard_deviation_ms;
 
   // Residual echo detector likelihood.
-  rtc::Optional<double> residual_echo_likelihood;
+  absl::optional<double> residual_echo_likelihood;
   // Maximum residual echo likelihood from the last time period.
-  rtc::Optional<double> residual_echo_likelihood_recent_max;
+  absl::optional<double> residual_echo_likelihood_recent_max;
 
   // The instantaneous delay estimate produced in the AEC. The unit is in
   // milliseconds and the value is the instantaneous value at the time of the
   // call to |GetStatistics()|.
-  rtc::Optional<int32_t> delay_ms;
+  absl::optional<int32_t> delay_ms;
 };
 
 }  // namespace webrtc