Use absl::make_unique and absl::WrapUnique directly

Instead of going through our wrappers in ptr_util.h.

This CL was generated by the following script:

  git grep -l ptr_util | xargs perl -pi -e 's,#include "rtc_base/ptr_util.h",#include "absl/memory/memory.h",'
  git grep -l MakeUnique | xargs perl -pi -e 's,\b(rtc::)?MakeUnique\b,absl::make_unique,g'
  git grep -l WrapUnique | xargs perl -pi -e 's,\b(rtc::)?WrapUnique\b,absl::WrapUnique,g'
  git checkout -- rtc_base/ptr_util{.h,_unittest.cc}
  git cl format

Followed by manually adding dependencies on
//third_party/abseil-cpp/absl/memory until `gn check` stopped
complaining.

Bug: webrtc:9473
Change-Id: I89ccd363f070479b8c431eb2c3d404a46eaacc1c
Reviewed-on: https://webrtc-review.googlesource.com/86600
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23850}

modules/audio_coding/audio_network_adaptor/event_log_writer.cc

@@ -12,10 +12,10 @@
 
 #include <algorithm>
 
+#include "absl/memory/memory.h"
 #include "logging/rtc_event_log/events/rtc_event_audio_network_adaptation.h"
 #include "logging/rtc_event_log/rtc_event_log.h"
 #include "modules/audio_coding/audio_network_adaptor/event_log_writer.h"
-#include "rtc_base/ptr_util.h"
 
 namespace webrtc {
 
@@ -63,9 +63,9 @@ void EventLogWriter::MaybeLogEncoderConfig(
 }
 
 void EventLogWriter::LogEncoderConfig(const AudioEncoderRuntimeConfig& config) {
-  auto config_copy = rtc::MakeUnique<AudioEncoderRuntimeConfig>(config);
-  event_log_->Log(
-      rtc::MakeUnique<RtcEventAudioNetworkAdaptation>(std::move(config_copy)));
+  auto config_copy = absl::make_unique<AudioEncoderRuntimeConfig>(config);
+  event_log_->Log(absl::make_unique<RtcEventAudioNetworkAdaptation>(
+      std::move(config_copy)));
   last_logged_config_ = config;
 }