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/call/bitrate_estimator_tests.cc b/call/bitrate_estimator_tests.cc
index 803e1f9..8fa3a57 100644
--- a/call/bitrate_estimator_tests.cc
+++ b/call/bitrate_estimator_tests.cc
@@ -12,7 +12,6 @@
 #include <memory>
 #include <string>
 
-#include "absl/memory/memory.h"
 #include "call/call.h"
 #include "call/fake_network_pipe.h"
 #include "call/simulated_network.h"
@@ -108,15 +107,15 @@
 
       send_transport_.reset(new test::DirectTransport(
           &task_queue_,
-          absl::make_unique<FakeNetworkPipe>(
-              Clock::GetRealTimeClock(), absl::make_unique<SimulatedNetwork>(
+          std::make_unique<FakeNetworkPipe>(
+              Clock::GetRealTimeClock(), std::make_unique<SimulatedNetwork>(
                                              BuiltInNetworkBehaviorConfig())),
           sender_call_.get(), payload_type_map_));
       send_transport_->SetReceiver(receiver_call_->Receiver());
       receive_transport_.reset(new test::DirectTransport(
           &task_queue_,
-          absl::make_unique<FakeNetworkPipe>(
-              Clock::GetRealTimeClock(), absl::make_unique<SimulatedNetwork>(
+          std::make_unique<FakeNetworkPipe>(
+              Clock::GetRealTimeClock(), std::make_unique<SimulatedNetwork>(
                                              BuiltInNetworkBehaviorConfig())),
           receiver_call_.get(), payload_type_map_));
       receive_transport_->SetReceiver(sender_call_->Receiver());
@@ -171,14 +170,14 @@
           send_stream_(nullptr),
           frame_generator_capturer_(),
           decoder_factory_(
-              []() { return absl::make_unique<test::FakeDecoder>(); }) {
+              []() { return std::make_unique<test::FakeDecoder>(); }) {
       test_->GetVideoSendConfig()->rtp.ssrcs[0]++;
       send_stream_ = test_->sender_call_->CreateVideoSendStream(
           test_->GetVideoSendConfig()->Copy(),
           test_->GetVideoEncoderConfig()->Copy());
       RTC_DCHECK_EQ(1, test_->GetVideoEncoderConfig()->number_of_streams);
       frame_generator_capturer_ =
-          absl::make_unique<test::FrameGeneratorCapturer>(
+          std::make_unique<test::FrameGeneratorCapturer>(
               test->clock_,
               test::FrameGenerator::CreateSquareGenerator(
                   kDefaultWidth, kDefaultHeight, absl::nullopt, absl::nullopt),