Replace rtc::Optional with absl::optional in pc

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

This CL generated by running script with parameter 'pc'

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: Ide3b9eb32df7f25991f898ac58fcb119c9f8ae12
Reviewed-on: https://webrtc-review.googlesource.com/84181
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23669}
diff --git a/pc/rtptransport_unittest.cc b/pc/rtptransport_unittest.cc
index 97ea2e4..7e4eb84 100644
--- a/pc/rtptransport_unittest.cc
+++ b/pc/rtptransport_unittest.cc
@@ -78,8 +78,8 @@
   bool ready() const { return ready_; }
   void OnReadyToSend(bool ready) { ready_ = ready; }
 
-  rtc::Optional<rtc::NetworkRoute> network_route() { return network_route_; }
-  void OnNetworkRouteChanged(rtc::Optional<rtc::NetworkRoute> network_route) {
+  absl::optional<rtc::NetworkRoute> network_route() { return network_route_; }
+  void OnNetworkRouteChanged(absl::optional<rtc::NetworkRoute> network_route) {
     network_route_ = std::move(network_route);
   }
 
@@ -102,7 +102,7 @@
   int rtcp_transport_sent_count_ = 0;
   RtpTransport* transport_ = nullptr;
   bool ready_ = false;
-  rtc::Optional<rtc::NetworkRoute> network_route_;
+  absl::optional<rtc::NetworkRoute> network_route_;
 };
 
 TEST(RtpTransportTest, SettingRtcpAndRtpSignalsReady) {
@@ -184,7 +184,7 @@
   network_route.remote_network_id = kRemoteNetId;
   network_route.last_sent_packet_id = kLastPacketId;
   network_route.packet_overhead = kTransportOverheadPerPacket;
-  fake_rtp.SetNetworkRoute(rtc::Optional<rtc::NetworkRoute>(network_route));
+  fake_rtp.SetNetworkRoute(absl::optional<rtc::NetworkRoute>(network_route));
   transport.SetRtpPacketTransport(&fake_rtp);
   ASSERT_TRUE(observer.network_route());
   EXPECT_EQ(network_route, *(observer.network_route()));
@@ -211,7 +211,7 @@
   network_route.remote_network_id = kRemoteNetId;
   network_route.last_sent_packet_id = kLastPacketId;
   network_route.packet_overhead = kTransportOverheadPerPacket;
-  fake_rtcp.SetNetworkRoute(rtc::Optional<rtc::NetworkRoute>(network_route));
+  fake_rtcp.SetNetworkRoute(absl::optional<rtc::NetworkRoute>(network_route));
   transport.SetRtcpPacketTransport(&fake_rtcp);
   ASSERT_TRUE(observer.network_route());
   EXPECT_EQ(network_route, *(observer.network_route()));