Migrate modules/video_coding to webrtc::Mutex.

Bug: webrtc:11567
Change-Id: I8023fbe7595f7ba8ae7c7db3583fc2e560ec3df2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/178803
Commit-Queue: Markus Handell <handellm@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31644}
diff --git a/modules/video_coding/deprecated/nack_module.cc b/modules/video_coding/deprecated/nack_module.cc
index 8658729..f8cfd34 100644
--- a/modules/video_coding/deprecated/nack_module.cc
+++ b/modules/video_coding/deprecated/nack_module.cc
@@ -115,7 +115,7 @@
 int DEPRECATED_NackModule::OnReceivedPacket(uint16_t seq_num,
                                             bool is_keyframe,
                                             bool is_recovered) {
-  rtc::CritScope lock(&crit_);
+  MutexLock lock(&mutex_);
   // TODO(philipel): When the packet includes information whether it is
   //                 retransmitted or not, use that value instead. For
   //                 now set it to true, which will cause the reordering
@@ -184,7 +184,7 @@
 }
 
 void DEPRECATED_NackModule::ClearUpTo(uint16_t seq_num) {
-  rtc::CritScope lock(&crit_);
+  MutexLock lock(&mutex_);
   nack_list_.erase(nack_list_.begin(), nack_list_.lower_bound(seq_num));
   keyframe_list_.erase(keyframe_list_.begin(),
                        keyframe_list_.lower_bound(seq_num));
@@ -193,12 +193,12 @@
 }
 
 void DEPRECATED_NackModule::UpdateRtt(int64_t rtt_ms) {
-  rtc::CritScope lock(&crit_);
+  MutexLock lock(&mutex_);
   rtt_ms_ = rtt_ms;
 }
 
 void DEPRECATED_NackModule::Clear() {
-  rtc::CritScope lock(&crit_);
+  MutexLock lock(&mutex_);
   nack_list_.clear();
   keyframe_list_.clear();
   recovered_list_.clear();
@@ -213,7 +213,7 @@
   if (nack_sender_) {
     std::vector<uint16_t> nack_batch;
     {
-      rtc::CritScope lock(&crit_);
+      MutexLock lock(&mutex_);
       nack_batch = GetNackBatch(kTimeOnly);
     }