Support for AudioContextOptions latencyHint.

third_party/WebKit/Source/modules/webaudio/DefaultAudioDestinationNode.cpp

 /*
  * Copyright (C) 2011, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 13 matching lines @@
  */
 
 #include "modules/webaudio/DefaultAudioDestinationNode.h"
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/dom/ExceptionCode.h"
 #include "modules/webaudio/BaseAudioContext.h"
 
 namespace blink {
 
-DefaultAudioDestinationHandler::DefaultAudioDestinationHandler(AudioNode& node)
+DefaultAudioDestinationHandler::DefaultAudioDestinationHandler(
+    AudioNode& node,
+    const WebAudioLatencyHint& latencyHint)
     : AudioDestinationHandler(node, AudioDestination::hardwareSampleRate()),
-      m_numberOfInputChannels(0) {
+      m_numberOfInputChannels(0),
+      m_latencyHint(latencyHint) {
   // Node-specific default mixing rules.
   m_channelCount = 2;
   setInternalChannelCountMode(Explicit);
   setInternalChannelInterpretation(AudioBus::Speakers);
 }
 
 PassRefPtr<DefaultAudioDestinationHandler>
-DefaultAudioDestinationHandler::create(AudioNode& node) {
-  return adoptRef(new DefaultAudioDestinationHandler(node));
+DefaultAudioDestinationHandler::create(AudioNode& node,
+                                       const WebAudioLatencyHint& latencyHint) {
+  return adoptRef(new DefaultAudioDestinationHandler(node, latencyHint));
 }
 
 DefaultAudioDestinationHandler::~DefaultAudioDestinationHandler() {
   DCHECK(!isInitialized());
 }
 
 void DefaultAudioDestinationHandler::dispose() {
   uninitialize();
   AudioDestinationHandler::dispose();
 }
@@ skipping 12 matching lines @@
   if (!isInitialized())
     return;
 
   m_destination->stop();
   m_numberOfInputChannels = 0;
 
   AudioHandler::uninitialize();
 }
 
 void DefaultAudioDestinationHandler::createDestination() {
-  float hardwareSampleRate = AudioDestination::hardwareSampleRate();
-  VLOG(1) << ">>>> hardwareSampleRate = " << hardwareSampleRate;

[Raymond Toy, 2016/11/15 18:16:17]

I hope we didn't lose this log print.  It's really useful on Android to get the
sample rate displayed.

[Andrew MacPherson, 2016/11/16 10:58:29]

Should I re-add the log print though we won't pass the hardwareSampleRate into
the AudioDestination or should the log print be moved to the 'content' side
where the hardware sample rate will be determined?

-
   m_destination = AudioDestination::create(
       *this, m_inputDeviceId, m_numberOfInputChannels, channelCount(),
-      hardwareSampleRate, context()->getSecurityOrigin());
+      m_latencyHint, context()->getSecurityOrigin());
 }
 
 void DefaultAudioDestinationHandler::startRendering() {
   DCHECK(isInitialized());
   if (isInitialized()) {
     DCHECK(!m_destination->isPlaying());
     m_destination->start();
   }
 }
 
@@ skipping 35 matching lines @@
     // Re-create destination.
     m_destination->stop();
     createDestination();
     m_destination->start();
   }
 }
 
 // ----------------------------------------------------------------
 
 DefaultAudioDestinationNode::DefaultAudioDestinationNode(
-    BaseAudioContext& context)
+    BaseAudioContext& context,
+    const WebAudioLatencyHint& latencyHint)
     : AudioDestinationNode(context) {
-  setHandler(DefaultAudioDestinationHandler::create(*this));
+  setHandler(DefaultAudioDestinationHandler::create(*this, latencyHint));
 }
 
 DefaultAudioDestinationNode* DefaultAudioDestinationNode::create(
-    BaseAudioContext* context) {
-  return new DefaultAudioDestinationNode(*context);
+    BaseAudioContext* context,
+    const WebAudioLatencyHint& latencyHint) {
+  return new DefaultAudioDestinationNode(*context, latencyHint);
 }
 
 }  // namespace blink