Support AudioContextOptions latencyHint as double.

media/base/audio_latency.cc

 // Copyright 2016 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.
 
 #include "media/base/audio_latency.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 
 #include "base/logging.h"
+#include "base/time/time.h"
 #include "build/build_config.h"
 
 namespace media {
 
 namespace {
 #if !defined(OS_WIN)
 // Taken from "Bit Twiddling Hacks"
 // http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
 uint32_t RoundUpToPowerOfTwo(uint32_t v) {
   v--;
@@ skipping 97 matching lines @@
   // the jitter.
   const int kSmallBufferSize = 1024;
   const int kDefaultCallbackBufferSize = 2048;
   if (hardware_buffer_size <= kSmallBufferSize)
     return kDefaultCallbackBufferSize;
 #endif
 
   return hardware_buffer_size;
 }
 
+int AudioLatency::GetExactBufferSize(base::TimeDelta duration,
+                                     int sample_rate,
+                                     int hardware_buffer_size) {
+  const double requested_buffer_size = duration.InSecondsF() * sample_rate;
+
+  DCHECK_NE(0, hardware_buffer_size);
+
+  // Round the requested size to the nearest multiple of the hardware size
+  const int buffer_size =
+      std::round(std::max(requested_buffer_size, 1.0) / hardware_buffer_size) *
+      hardware_buffer_size;
+
+  return std::max(buffer_size, hardware_buffer_size);
+}
+
 }  // namespace media