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}
diff --git a/video/rtp_video_stream_receiver_unittest.cc b/video/rtp_video_stream_receiver_unittest.cc
index b6d049e..abc00eb 100644
--- a/video/rtp_video_stream_receiver_unittest.cc
+++ b/video/rtp_video_stream_receiver_unittest.cc
@@ -11,6 +11,7 @@
 #include "test/gmock.h"
 #include "test/gtest.h"
 
+#include "absl/memory/memory.h"
 #include "common_video/h264/h264_common.h"
 #include "media/base/mediaconstants.h"
 #include "modules/pacing/packet_router.h"
@@ -22,7 +23,6 @@
 #include "modules/video_coding/rtp_frame_reference_finder.h"
 #include "rtc_base/bytebuffer.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/ptr_util.h"
 #include "system_wrappers/include/clock.h"
 #include "system_wrappers/include/field_trial_default.h"
 #include "test/field_trial.h"
@@ -102,7 +102,7 @@
 std::unique_ptr<RtpPacketReceived> CreateRtpPacketReceived(
     uint32_t ssrc = kSsrc,
     uint16_t sequence_number = kSequenceNumber) {
-  auto packet = rtc::MakeUnique<RtpPacketReceived>();
+  auto packet = absl::make_unique<RtpPacketReceived>();
   packet->SetSsrc(ssrc);
   packet->SetSequenceNumber(sequence_number);
   return packet;
@@ -125,8 +125,8 @@
 
   void SetUp() {
     rtp_receive_statistics_ =
-        rtc::WrapUnique(ReceiveStatistics::Create(Clock::GetRealTimeClock()));
-    rtp_video_stream_receiver_ = rtc::MakeUnique<RtpVideoStreamReceiver>(
+        absl::WrapUnique(ReceiveStatistics::Create(Clock::GetRealTimeClock()));
+    rtp_video_stream_receiver_ = absl::make_unique<RtpVideoStreamReceiver>(
         &mock_transport_, nullptr, &packet_router_, &config_,
         rtp_receive_statistics_.get(), nullptr, process_thread_.get(),
         &mock_nack_sender_, &mock_key_frame_request_sender_,