Qualify cmath functions.

Bug: None
Change-Id: Ibfc3bbe5a21743b623ab01ae9e021d322aee2a94
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/128083
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27174}
diff --git a/audio/remix_resample_unittest.cc b/audio/remix_resample_unittest.cc
index f1fb5f7..25af6e7 100644
--- a/audio/remix_resample_unittest.cc
+++ b/audio/remix_resample_unittest.cc
@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include <math.h>
+#include <cmath>
 
 #include "audio/remix_resample.h"
 #include "common_audio/resampler/include/push_resampler.h"
@@ -133,7 +133,7 @@
     }
     float snr = 100;  // We assign 100 dB to the zero-error case.
     if (mse > 0)
-      snr = 10 * log10(variance / mse);
+      snr = 10 * std::log10(variance / mse);
     if (snr > best_snr) {
       best_snr = snr;
       best_delay = delay;