Update to current webrtc library

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

webrtc/modules/audio_processing/agc2/rnn_vad/common.cc

@@ -0,0 +1,34 @@
+/*
+ *  Copyright (c) 2019 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 "modules/audio_processing/agc2/rnn_vad/common.h"
+
+#include "rtc_base/system/arch.h"
+#include "system_wrappers/include/cpu_features_wrapper.h"
+
+namespace webrtc {
+namespace rnn_vad {
+
+Optimization DetectOptimization() {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+  if (GetCPUInfo(kSSE2) != 0) {
+    return Optimization::kSse2;
+  }
+#endif
+
+#if defined(WEBRTC_HAS_NEON)
+  return Optimization::kNeon;
+#endif
+
+  return Optimization::kNone;
+}
+
+}  // namespace rnn_vad
+}  // namespace webrtc