Support for AudioContextOptions latencyHint.

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

 /*
  * Copyright (C) 2010, 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 27 matching lines @@
 #include <stdio.h>
 #endif
 
 namespace blink {
 
 AudioHandler::AudioHandler(NodeType nodeType, AudioNode& node, float sampleRate)
     : m_isInitialized(false),
       m_nodeType(NodeTypeUnknown),
       m_node(&node),
       m_context(node.context()),
-      m_sampleRate(sampleRate),
       m_lastProcessingTime(-1),
       m_lastNonSilentTime(-1),
       m_connectionRefCount(0),
       m_isDisabled(false),
       m_channelCount(2) {
   setNodeType(nodeType);
   setInternalChannelCountMode(Max);
   setInternalChannelInterpretation(AudioBus::Speakers);
 
 #if DEBUG_AUDIONODE_REFERENCES
@@ skipping 257 matching lines @@
   // have the results cached in their bus;
   double currentTime = context()->currentTime();
   if (m_lastProcessingTime != currentTime) {
     // important to first update this time because of feedback loops in the
     // rendering graph.
     m_lastProcessingTime = currentTime;
 
     pullInputs(framesToProcess);
 
     bool silentInputs = inputsAreSilent();
-    if (!silentInputs)
+    if (!silentInputs) {
       m_lastNonSilentTime =
           (context()->currentSampleFrame() + framesToProcess) /
-          static_cast<double>(m_sampleRate);
+          static_cast<double>(context()->sampleRate());
+    }
 
     if (silentInputs && propagatesSilence()) {
       silenceOutputs();
     } else {
       // Unsilence the outputs first because the processing of the node may
       // cause the outputs to go silent and we want to propagate that hint to
       // the downstream nodes.  (For example, a Gain node with a gain of 0 will
       // want to silence its output.)
       unsilenceOutputs();
       process(framesToProcess);
@@ skipping 604 matching lines @@
 }
 
 void AudioNode::didAddOutput(unsigned numberOfOutputs) {
   m_connectedNodes.append(nullptr);
   DCHECK_EQ(numberOfOutputs, m_connectedNodes.size());
   m_connectedParams.append(nullptr);
   DCHECK_EQ(numberOfOutputs, m_connectedParams.size());
 }
 
 }  // namespace blink