Update to current webrtc library

This is from the upstream library commit id
3326535126e435f1ba647885ce43a8f0f3d317eb, corresponding to Chromium
88.0.4290.1.

webrtc/rtc_base/synchronization/rw_lock_win.cc

@@ -0,0 +1,41 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "rtc_base/synchronization/rw_lock_win.h"
+
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+
+RWLockWin::RWLockWin() {
+  InitializeSRWLock(&lock_);
+}
+
+RWLockWin* RWLockWin::Create() {
+  return new RWLockWin();
+}
+
+void RWLockWin::AcquireLockExclusive() {
+  AcquireSRWLockExclusive(&lock_);
+}
+
+void RWLockWin::ReleaseLockExclusive() {
+  ReleaseSRWLockExclusive(&lock_);
+}
+
+void RWLockWin::AcquireLockShared() {
+  AcquireSRWLockShared(&lock_);
+}
+
+void RWLockWin::ReleaseLockShared() {
+  ReleaseSRWLockShared(&lock_);
+}
+
+}  // namespace webrtc