Bump to WebRTC M120 release

Some API deprecation -- ExperimentalAgc and ExperimentalNs are gone.
We're continuing to carry iSAC even though it's gone upstream, but maybe
we'll want to drop that soon.

webrtc/modules/audio_processing/agc2/cpu_features.cc

@@ -0,0 +1,62 @@
+/*
+ *  Copyright (c) 2020 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/cpu_features.h"
+
+#include "rtc_base/strings/string_builder.h"
+#include "rtc_base/system/arch.h"
+#include "system_wrappers/include/cpu_features_wrapper.h"
+
+namespace webrtc {
+
+std::string AvailableCpuFeatures::ToString() const {
+  char buf[64];
+  rtc::SimpleStringBuilder builder(buf);
+  bool first = true;
+  if (sse2) {
+    builder << (first ? "SSE2" : "_SSE2");
+    first = false;
+  }
+  if (avx2) {
+    builder << (first ? "AVX2" : "_AVX2");
+    first = false;
+  }
+  if (neon) {
+    builder << (first ? "NEON" : "_NEON");
+    first = false;
+  }
+  if (first) {
+    return "none";
+  }
+  return builder.str();
+}
+
+// Detects available CPU features.
+AvailableCpuFeatures GetAvailableCpuFeatures() {
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+  return {/*sse2=*/GetCPUInfo(kSSE2) != 0,
+          /*avx2=*/GetCPUInfo(kAVX2) != 0,
+          /*neon=*/false};
+#elif defined(WEBRTC_HAS_NEON)
+  return {/*sse2=*/false,
+          /*avx2=*/false,
+          /*neon=*/true};
+#else
+  return {/*sse2=*/false,
+          /*avx2=*/false,
+          /*neon=*/false};
+#endif
+}
+
+AvailableCpuFeatures NoAvailableCpuFeatures() {
+  return {/*sse2=*/false, /*avx2=*/false, /*neon=*/false};
+}
+
+}  // namespace webrtc