Add SafeMin() and SafeMax(), which accept args of different types

webrtc/modules/audio_coding/neteq/merge.cc

Index: webrtc/modules/audio_coding/neteq/merge.cc
diff --git a/webrtc/modules/audio_coding/neteq/merge.cc b/webrtc/modules/audio_coding/neteq/merge.cc
index 299682f60d44b260bf5a5e99fb8eb9ff5c8cb583..d50b66588a8d2e146905ea47a83a55bb4a2ada31 100644
--- a/webrtc/modules/audio_coding/neteq/merge.cc
+++ b/webrtc/modules/audio_coding/neteq/merge.cc
@@ -16,6 +16,8 @@
 #include <algorithm>  // min, max
 #include <memory>
 
+#include "webrtc/base/safe_conversions.h"
+#include "webrtc/base/safe_minmax.h"
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 #include "webrtc/modules/audio_coding/neteq/audio_multi_vector.h"
 #include "webrtc/modules/audio_coding/neteq/cross_correlation.h"
@@ -209,8 +211,8 @@ size_t Merge::GetExpandedSignal(size_t* old_length, size_t* expand_period) {
 int16_t Merge::SignalScaling(const int16_t* input, size_t input_length,
                              const int16_t* expanded_signal) const {
   // Adjust muting factor if new vector is more or less of the BGN energy.
-  const size_t mod_input_length =
-      std::min(static_cast<size_t>(64 * fs_mult_), input_length);
+  const auto mod_input_length = rtc::SafeMin<size_t>(
+      64 * rtc::dchecked_cast<size_t>(fs_mult_), input_length);
   const int16_t expanded_max =
       WebRtcSpl_MaxAbsValueW16(expanded_signal, mod_input_length);
   int32_t factor = (expanded_max * expanded_max) /