Express audio delay more precisely in frames rather than milliseconds.

media/audio/audio_parameters.cc

 // 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.
 
 #include "media/audio/audio_parameters.h"
 
 #include "base/logging.h"
 #include "media/base/limits.h"
 
 namespace media {
@@ skipping 59 matching lines @@
 }
 
 int AudioParameters::GetBytesPerSecond() const {
   return sample_rate_ * GetBytesPerFrame();
 }
 
 int AudioParameters::GetBytesPerFrame() const {
   return channels_ * bits_per_sample_ / 8;
 }
 
+double AudioParameters::GetMicrosecondsPerFrame() const {
+  return static_cast<double>(base::Time::kMicrosecondsPerSecond) / sample_rate_;
+}
+
 base::TimeDelta AudioParameters::GetBufferDuration() const {
   return base::TimeDelta::FromMicroseconds(static_cast<int64_t>(
       frames_per_buffer_ * base::Time::kMicrosecondsPerSecond /
       static_cast<float>(sample_rate_)));
 }
 
 bool AudioParameters::Equals(const AudioParameters& other) const {
   return format_ == other.format() && sample_rate_ == other.sample_rate() &&
          channel_layout_ == other.channel_layout() &&
          channels_ == other.channels() &&
          bits_per_sample_ == other.bits_per_sample() &&
          frames_per_buffer_ == other.frames_per_buffer() &&
          effects_ == other.effects() && mic_positions_ == other.mic_positions_;
 }
 
 }  // namespace media