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 "build/build_config.h"
+#include "media/base/audio_parameters.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--;
   v |= v >> 1;
@@ skipping 96 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(double duration,
+                                     const AudioParameters& hardware_params) {
+  return std::max(
+      std::min(static_cast<int>(duration * hardware_params.sample_rate()),
+               GetHighLatencyBufferSize(hardware_params.sample_rate(), 0)),
+      static_cast<int>(hardware_params.frames_per_buffer()));
+}
+
 }  // namespace media