Replace AudioSilenceDetector with an AudioPowerMonitor.

base/float_util.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_FLOAT_UTIL_H_
 #define BASE_FLOAT_UTIL_H_
 
 #include "build/build_config.h"
 
 #include <float.h>
 
 #include <cmath>
 
 namespace base {
 
-inline bool IsFinite(const double& number) {
+template <typename Float>
+inline bool IsFinite(const Float& number) {
 #if defined(OS_POSIX)
   return std::isfinite(number) != 0;
 #elif defined(OS_WIN)
   return _finite(number) != 0;
 #endif
 }
 
+template <typename Float>
+inline bool IsNaN(const Float& number) {
+#if defined(OS_POSIX)
+  return std::isnan(number) != 0;
+#elif defined(OS_WIN)
+  return _isnan(number) != 0;
+#endif
+}
+
 }  // namespace base
 
 #endif  // BASE_FLOAT_UTIL_H_