Support AudioContextOptions latencyHint as double.

media/base/audio_latency.h

Index: media/base/audio_latency.h
diff --git a/media/base/audio_latency.h b/media/base/audio_latency.h
index c6c44f9cebd70176766d097adf47db42af19feb2..c9112694be283b020e94f13bbbad47ab2bd0013c 100644
--- a/media/base/audio_latency.h
+++ b/media/base/audio_latency.h
@@ -9,6 +9,8 @@
 
 namespace media {
 
+class AudioParameters;
+
 class MEDIA_EXPORT AudioLatency {
  public:
   // Categories of expected latencies for input/output audio. Do not change
@@ -35,6 +37,9 @@ class MEDIA_EXPORT AudioLatency {
   static int GetRtcBufferSize(int sample_rate, int hardware_buffer_size);
 
   static int GetInteractiveBufferSize(int hardware_buffer_size);
+
+  static int GetExactBufferSize(double duration,

[o1ka, 2017/03/17 11:17:22]

|duration_in_seconds| would be more descriptive

+                                const AudioParameters& hardware_params);
 };
 
 }  // namespace media