Use std::make_unique instead of absl::make_unique.

WebRTC is now using C++14 so there is no need to use the Abseil version
of std::make_unique.

This CL has been created with the following steps:

git grep -l absl::make_unique | sort | uniq > /tmp/make_unique.txt
git grep -l absl::WrapUnique | sort | uniq > /tmp/wrap_unique.txt
git grep -l "#include <memory>" | sort | uniq > /tmp/memory.txt

diff --new-line-format="" --unchanged-line-format="" \
  /tmp/make_unique.txt /tmp/wrap_unique.txt | sort | \
  uniq > /tmp/only_make_unique.txt
diff --new-line-format="" --unchanged-line-format="" \
  /tmp/only_make_unique.txt /tmp/memory.txt | \
  xargs grep -l "absl/memory" > /tmp/add-memory.txt

git grep -l "\babsl::make_unique\b" | \
  xargs sed -i "s/\babsl::make_unique\b/std::make_unique/g"

git checkout PRESUBMIT.py abseil-in-webrtc.md

cat /tmp/add-memory.txt | \
  xargs sed -i \
  's/#include "absl\/memory\/memory.h"/#include <memory>/g'
git cl format
# Manual fix order of the new inserted #include <memory>

cat /tmp/only_make_unique | xargs grep -l "#include <memory>" | \
  xargs sed -i '/#include "absl\/memory\/memory.h"/d'

git ls-files | grep BUILD.gn | \
  xargs sed -i '/\/\/third_party\/abseil-cpp\/absl\/memory/d'

python tools_webrtc/gn_check_autofix.py \
  -m tryserver.webrtc -b linux_rel

# Repead the gn_check_autofix step for other platforms

git ls-files | grep BUILD.gn | \
  xargs sed -i 's/absl\/memory:memory/absl\/memory/g'
git cl format

Bug: webrtc:10945
Change-Id: I3fe28ea80f4dd3ba3cf28effd151d5e1f19aff89
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/153221
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29209}
diff --git a/modules/rtp_rtcp/source/rtcp_transceiver_unittest.cc b/modules/rtp_rtcp/source/rtcp_transceiver_unittest.cc
index 12bf49c..8be17ca 100644
--- a/modules/rtp_rtcp/source/rtcp_transceiver_unittest.cc
+++ b/modules/rtp_rtcp/source/rtcp_transceiver_unittest.cc
@@ -12,7 +12,6 @@
 
 #include <memory>
 
-#include "absl/memory/memory.h"
 #include "modules/rtp_rtcp/source/rtcp_packet/sender_report.h"
 #include "modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 #include "rtc_base/event.h"
@@ -79,7 +78,7 @@
 
   std::unique_ptr<RtcpTransceiver> rtcp_transceiver;
   queue.PostTask([&] {
-    rtcp_transceiver = absl::make_unique<RtcpTransceiver>(config);
+    rtcp_transceiver = std::make_unique<RtcpTransceiver>(config);
     rtcp_transceiver->SendCompoundPacket();
   });
   WaitPostedTasks(&queue);
@@ -91,7 +90,7 @@
   RtcpTransceiverConfig config;
   config.outgoing_transport = &outgoing_transport;
   config.task_queue = &queue;
-  auto rtcp_transceiver = absl::make_unique<RtcpTransceiver>(config);
+  auto rtcp_transceiver = std::make_unique<RtcpTransceiver>(config);
 
   queue.PostTask([&] {
     // Insert a packet just before destruction to test for races.
@@ -162,7 +161,7 @@
   RtcpTransceiver rtcp_transceiver(config);
   rtc::Event observer_deleted;
 
-  auto observer = absl::make_unique<MockMediaReceiverRtcpObserver>();
+  auto observer = std::make_unique<MockMediaReceiverRtcpObserver>();
   EXPECT_CALL(*observer, OnSenderReport(kRemoteSsrc, _, 1));
   EXPECT_CALL(*observer, OnSenderReport(kRemoteSsrc, _, 2)).Times(0);
 
@@ -187,7 +186,7 @@
   config.outgoing_transport = &null_transport;
   config.task_queue = &queue;
   RtcpTransceiver rtcp_transceiver(config);
-  auto observer = absl::make_unique<MockMediaReceiverRtcpObserver>();
+  auto observer = std::make_unique<MockMediaReceiverRtcpObserver>();
   rtcp_transceiver.AddMediaReceiverRtcpObserver(kRemoteSsrc, observer.get());
 
   rtc::Event queue_blocker;
@@ -241,7 +240,7 @@
   config.task_queue = &queue;
   config.schedule_periodic_compound_packets = true;
 
-  auto rtcp_transceiver = absl::make_unique<RtcpTransceiver>(config);
+  auto rtcp_transceiver = std::make_unique<RtcpTransceiver>(config);
   rtc::Event done;
   rtcp_transceiver->SendCompoundPacket();
   rtcp_transceiver->Stop([&] {