Replace rtc::Optional with absl::optional in modules/audio_coding

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_coding'

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: Ic980ee605148fdb160666d4aa03cc87175e48fe8
Reviewed-on: https://webrtc-review.googlesource.com/84130
Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23659}
diff --git a/modules/audio_coding/neteq/decoder_database.h b/modules/audio_coding/neteq/decoder_database.h
index f769e39..6b388dd 100644
--- a/modules/audio_coding/neteq/decoder_database.h
+++ b/modules/audio_coding/neteq/decoder_database.h
@@ -43,14 +43,14 @@
   class DecoderInfo {
    public:
     DecoderInfo(const SdpAudioFormat& audio_format,
-                rtc::Optional<AudioCodecPairId> codec_pair_id,
+                absl::optional<AudioCodecPairId> codec_pair_id,
                 AudioDecoderFactory* factory,
                 const std::string& codec_name);
     explicit DecoderInfo(const SdpAudioFormat& audio_format,
-                         rtc::Optional<AudioCodecPairId> codec_pair_id,
+                         absl::optional<AudioCodecPairId> codec_pair_id,
                          AudioDecoderFactory* factory = nullptr);
     explicit DecoderInfo(NetEqDecoder ct,
-                         rtc::Optional<AudioCodecPairId> codec_pair_id,
+                         absl::optional<AudioCodecPairId> codec_pair_id,
                          AudioDecoderFactory* factory = nullptr);
     DecoderInfo(const SdpAudioFormat& audio_format,
                 AudioDecoder* ext_dec,
@@ -111,7 +111,7 @@
     const std::string name_;
 
     const SdpAudioFormat audio_format_;
-    const rtc::Optional<AudioCodecPairId> codec_pair_id_;
+    const absl::optional<AudioCodecPairId> codec_pair_id_;
     AudioDecoderFactory* const factory_;
     mutable std::unique_ptr<AudioDecoder> decoder_;
 
@@ -120,10 +120,10 @@
 
     // Set iff this is a comfort noise decoder.
     struct CngDecoder {
-      static rtc::Optional<CngDecoder> Create(const SdpAudioFormat& format);
+      static absl::optional<CngDecoder> Create(const SdpAudioFormat& format);
       int sample_rate_hz;
     };
-    const rtc::Optional<CngDecoder> cng_decoder_;
+    const absl::optional<CngDecoder> cng_decoder_;
 
     enum class Subtype : int8_t {
       kNormal,
@@ -143,7 +143,7 @@
 
   DecoderDatabase(
       const rtc::scoped_refptr<AudioDecoderFactory>& decoder_factory,
-      rtc::Optional<AudioCodecPairId> codec_pair_id);
+      absl::optional<AudioCodecPairId> codec_pair_id);
 
   virtual ~DecoderDatabase();
 
@@ -247,7 +247,7 @@
   int active_cng_decoder_type_;
   mutable std::unique_ptr<ComfortNoiseDecoder> active_cng_decoder_;
   rtc::scoped_refptr<AudioDecoderFactory> decoder_factory_;
-  const rtc::Optional<AudioCodecPairId> codec_pair_id_;
+  const absl::optional<AudioCodecPairId> codec_pair_id_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(DecoderDatabase);
 };