stats: replace new with std::make_unique

apart from the certificate stats which need to update the
reference to the previous certificate stats in the chain.

BUG=None

Change-Id: I27f58084b849fd9afe236e5b57139bedb8eb1811
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/274175
Commit-Queue: Philipp Hancke <phancke@microsoft.com>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38026}
diff --git a/api/stats/rtc_stats.h b/api/stats/rtc_stats.h
index a5fae52..2af9768 100644
--- a/api/stats/rtc_stats.h
+++ b/api/stats/rtc_stats.h
@@ -158,7 +158,7 @@
   const char this_class::kType[] = type_str;                                   \
                                                                                \
   std::unique_ptr<webrtc::RTCStats> this_class::copy() const {                 \
-    return std::unique_ptr<webrtc::RTCStats>(new this_class(*this));           \
+    return std::make_unique<this_class>(*this);                                \
   }                                                                            \
                                                                                \
   const char* this_class::type() const { return this_class::kType; }           \
@@ -189,7 +189,7 @@
   const char this_class::kType[] = type_str;                                \
                                                                             \
   std::unique_ptr<webrtc::RTCStats> this_class::copy() const {              \
-    return std::unique_ptr<webrtc::RTCStats>(new this_class(*this));        \
+    return std::make_unique<this_class>(*this);                             \
   }                                                                         \
                                                                             \
   const char* this_class::type() const { return this_class::kType; }        \
diff --git a/pc/rtc_stats_collector.cc b/pc/rtc_stats_collector.cc
index 084bd11..15e72c4 100644
--- a/pc/rtc_stats_collector.cc
+++ b/pc/rtc_stats_collector.cc
@@ -360,10 +360,10 @@
   RTC_DCHECK_LE(codec_params.payload_type, 127);
   RTC_DCHECK(codec_params.clock_rate);
   uint32_t payload_type = static_cast<uint32_t>(codec_params.payload_type);
-  std::unique_ptr<RTCCodecStats> codec_stats(
-      new RTCCodecStats(RTCCodecStatsIDFromTransportAndCodecParameters(
-                            direction, transport_id, codec_params),
-                        timestamp_us));
+  std::unique_ptr<RTCCodecStats> codec_stats(std::make_unique<RTCCodecStats>(
+      RTCCodecStatsIDFromTransportAndCodecParameters(direction, transport_id,
+                                                     codec_params),
+      timestamp_us));
   codec_stats->payload_type = payload_type;
   codec_stats->mime_type = codec_params.mime_type();
   if (codec_params.clock_rate) {
@@ -846,9 +846,11 @@
   if (!stats) {
     std::unique_ptr<RTCIceCandidateStats> candidate_stats;
     if (is_local)
-      candidate_stats.reset(new RTCLocalIceCandidateStats(id, timestamp_us));
+      candidate_stats =
+          std::make_unique<RTCLocalIceCandidateStats>(id, timestamp_us);
     else
-      candidate_stats.reset(new RTCRemoteIceCandidateStats(id, timestamp_us));
+      candidate_stats =
+          std::make_unique<RTCRemoteIceCandidateStats>(id, timestamp_us);
     candidate_stats->transport_id = transport_id;
     if (is_local) {
       candidate_stats->network_type =
@@ -920,7 +922,7 @@
     const cricket::VoiceSenderInfo& voice_sender_info,
     int attachment_id) {
   std::unique_ptr<RTCMediaStreamTrackStats> audio_track_stats(
-      new RTCMediaStreamTrackStats(
+      std::make_unique<RTCMediaStreamTrackStats>(
           RTCMediaStreamTrackStatsIDFromDirectionAndAttachment(
               kDirectionOutbound, attachment_id),
           timestamp_us, RTCMediaStreamTrackKind::kAudio));
@@ -955,7 +957,7 @@
   // Since receiver tracks can't be reattached, we use the SSRC as
   // an attachment identifier.
   std::unique_ptr<RTCMediaStreamTrackStats> audio_track_stats(
-      new RTCMediaStreamTrackStats(
+      std::make_unique<RTCMediaStreamTrackStats>(
           RTCMediaStreamTrackStatsIDFromDirectionAndAttachment(
               kDirectionInbound, attachment_id),
           timestamp_us, RTCMediaStreamTrackKind::kAudio));
@@ -1009,7 +1011,7 @@
     const cricket::VideoSenderInfo& video_sender_info,
     int attachment_id) {
   std::unique_ptr<RTCMediaStreamTrackStats> video_track_stats(
-      new RTCMediaStreamTrackStats(
+      std::make_unique<RTCMediaStreamTrackStats>(
           RTCMediaStreamTrackStatsIDFromDirectionAndAttachment(
               kDirectionOutbound, attachment_id),
           timestamp_us, RTCMediaStreamTrackKind::kVideo));
@@ -1038,7 +1040,7 @@
     const cricket::VideoReceiverInfo& video_receiver_info,
     int attachment_id) {
   std::unique_ptr<RTCMediaStreamTrackStats> video_track_stats(
-      new RTCMediaStreamTrackStats(
+      std::make_unique<RTCMediaStreamTrackStats>(
           RTCMediaStreamTrackStatsIDFromDirectionAndAttachment(
               kDirectionInbound, attachment_id),
           timestamp_us, RTCMediaStreamTrackKind::kVideo));
@@ -1667,8 +1669,8 @@
   std::vector<DataChannelStats> data_stats = pc_->GetDataChannelStats();
   for (const auto& stats : data_stats) {
     std::unique_ptr<RTCDataChannelStats> data_channel_stats(
-        new RTCDataChannelStats("D" + rtc::ToString(stats.internal_id),
-                                timestamp_us));
+        std::make_unique<RTCDataChannelStats>(
+            "D" + rtc::ToString(stats.internal_id), timestamp_us));
     data_channel_stats->label = std::move(stats.label);
     data_channel_stats->protocol = std::move(stats.protocol);
     data_channel_stats->data_channel_identifier = stats.id;
@@ -1699,7 +1701,7 @@
       for (const auto& info :
            channel_stats.ice_transport_stats.connection_infos) {
         std::unique_ptr<RTCIceCandidatePairStats> candidate_pair_stats(
-            new RTCIceCandidatePairStats(
+            std::make_unique<RTCIceCandidatePairStats>(
                 RTCIceCandidatePairStatsIDFromConnectionInfo(info),
                 timestamp_us));
 
@@ -1815,7 +1817,8 @@
   // Build stats for each stream ID known.
   for (auto& it : track_ids) {
     std::unique_ptr<RTCMediaStreamStats> stream_stats(
-        new RTCMediaStreamStats("DEPRECATED_S" + it.first, timestamp_us));
+        std::make_unique<RTCMediaStreamStats>("DEPRECATED_S" + it.first,
+                                              timestamp_us));
     stream_stats->stream_identifier = it.first;
     stream_stats->track_ids = it.second;
     report->AddStats(std::move(stream_stats));
@@ -1953,7 +1956,7 @@
   rtc::Thread::ScopedDisallowBlockingCalls no_blocking_calls;
 
   std::unique_ptr<RTCPeerConnectionStats> stats(
-      new RTCPeerConnectionStats("P", timestamp_us));
+      std::make_unique<RTCPeerConnectionStats>("P", timestamp_us));
   stats->data_channels_opened = internal_record_.data_channels_opened;
   stats->data_channels_closed = internal_record_.data_channels_closed;
   report->AddStats(std::move(stats));
@@ -2200,9 +2203,10 @@
     for (const cricket::TransportChannelStats& channel_stats :
          transport_stats.channel_stats) {
       std::unique_ptr<RTCTransportStats> transport_stats(
-          new RTCTransportStats(RTCTransportStatsIDFromTransportChannel(
-                                    transport_name, channel_stats.component),
-                                timestamp_us));
+          std::make_unique<RTCTransportStats>(
+              RTCTransportStatsIDFromTransportChannel(transport_name,
+                                                      channel_stats.component),
+              timestamp_us));
       transport_stats->packets_sent =
           channel_stats.ice_transport_stats.packets_sent;
       transport_stats->packets_received =
diff --git a/stats/rtcstats_objects.cc b/stats/rtcstats_objects.cc
index 321d8db..b1b081f 100644
--- a/stats/rtcstats_objects.cc
+++ b/stats/rtcstats_objects.cc
@@ -335,7 +335,7 @@
     : RTCIceCandidateStats(std::move(id), timestamp_us, false) {}
 
 std::unique_ptr<RTCStats> RTCLocalIceCandidateStats::copy() const {
-  return std::unique_ptr<RTCStats>(new RTCLocalIceCandidateStats(*this));
+  return std::make_unique<RTCLocalIceCandidateStats>(*this);
 }
 
 const char* RTCLocalIceCandidateStats::type() const {
@@ -353,7 +353,7 @@
     : RTCIceCandidateStats(std::move(id), timestamp_us, true) {}
 
 std::unique_ptr<RTCStats> RTCRemoteIceCandidateStats::copy() const {
-  return std::unique_ptr<RTCStats>(new RTCRemoteIceCandidateStats(*this));
+  return std::make_unique<RTCRemoteIceCandidateStats>(*this);
 }
 
 const char* RTCRemoteIceCandidateStats::type() const {