Support for AudioContextOptions latencyHint.

third_party/WebKit/Source/modules/webaudio/BaseAudioContext.idl

 // 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.
 
 // See https://webaudio.github.io/web-audio-api/#BaseAudioContext
 enum AudioContextState {
     "suspended",
     "running",
     "closed"
 };
@@ skipping 10 matching lines @@
 
     // All AudioNodes in the context run at this sample-rate (sample-frames per second).
     readonly attribute float sampleRate;
 
     // All panning is relative to this listener.
     readonly attribute AudioListener listener;
 
     // Current state of the AudioContext
     readonly attribute AudioContextState state;
 
+    // Number of seconds of processing latency incurred by the AudioContext passing the audio from the AudioDestinationNode to the audio subsystem

[Raymond Toy, 2016/11/30 21:50:27]

I think this is a spec issue (for which I've filed a bug).  baseLatency doesn't
make sense for an OfflineAudioContext so it shouldn't be in the
BaseAudioContext.

[Andrew MacPherson, 2016/12/01 12:11:56]

Done, I've moved this to the AudioContext now.

+    readonly attribute double baseLatency;
+
     [RaisesException] AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long numberOfFrames, float sampleRate);
 
     // Asynchronous audio file data decoding.
     [RaisesException, MeasureAs=AudioContextDecodeAudioData, CallWith=ScriptState] Promise<AudioBuffer> decodeAudioData(ArrayBuffer audioData, optional AudioBufferCallback successCallback, optional AudioBufferCallback errorCallback);
 
     // Sources
     [RaisesException, MeasureAs=AudioContextCreateBufferSource] AudioBufferSourceNode createBufferSource();
     [RaisesException, MeasureAs=AudioContextCreateConstantSource] ConstantSourceNode createConstantSource();
 
     // Processing nodes
@@ skipping 19 matching lines @@
     [MeasureAs=AudioContextResume, CallWith=ScriptState, ImplementedAs=resumeContext] Promise<void> resume();
 
     // TODO(rtoy): These really belong to the AudioContext, but we need them
     // here so we can use an offline audio context to test these.
     [RaisesException, MeasureAs=AudioContextCreateMediaElementSource] MediaElementAudioSourceNode createMediaElementSource(HTMLMediaElement mediaElement);
     [RaisesException, MeasureAs=AudioContextCreateMediaStreamSource] MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
     [RaisesException, MeasureAs=AudioContextCreateMediaStreamDestination] MediaStreamAudioDestinationNode createMediaStreamDestination();
 
     attribute EventHandler onstatechange;
 };