Implementation of 'AudioContext.getOutputTimestamp' method

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

Index: third_party/WebKit/Source/modules/webaudio/BaseAudioContext.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/BaseAudioContext.cpp b/third_party/WebKit/Source/modules/webaudio/BaseAudioContext.cpp
index d026540c47d147dc2e16d6f87e422ed128560208..ce29dc4ff142a0e5253712a313984fdfbffbc6ad 100644
--- a/third_party/WebKit/Source/modules/webaudio/BaseAudioContext.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/BaseAudioContext.cpp
@@ -102,7 +102,8 @@ BaseAudioContext::BaseAudioContext(Document* document)
       m_periodicWaveSine(nullptr),
       m_periodicWaveSquare(nullptr),
       m_periodicWaveSawtooth(nullptr),
-      m_periodicWaveTriangle(nullptr) {
+      m_periodicWaveTriangle(nullptr),
+      m_outputPosition() {
   // If mediaPlaybackRequiresUserGesture is enabled, cross origin iframes will
   // require user gesture for the AudioContext to produce sound.
   if (document->settings() &&
@@ -134,7 +135,8 @@ BaseAudioContext::BaseAudioContext(Document* document,
       m_periodicWaveSine(nullptr),
       m_periodicWaveSquare(nullptr),
       m_periodicWaveSawtooth(nullptr),
-      m_periodicWaveTriangle(nullptr) {}
+      m_periodicWaveTriangle(nullptr),
+      m_outputPosition() {}
 
 BaseAudioContext::~BaseAudioContext() {
   deferredTaskHandler().contextWillBeDestroyed();
@@ -705,7 +707,8 @@ void BaseAudioContext::handleStoppableSourceNodes() {
   }
 }
 
-void BaseAudioContext::handlePreRenderTasks() {
+void BaseAudioContext::handlePreRenderTasks(
+    const AudioIOPosition& outputPosition) {
   DCHECK(isAudioThread());
 
   // At the beginning of every render quantum, try to update the internal
@@ -723,6 +726,9 @@ void BaseAudioContext::handlePreRenderTasks() {
     // Update the dirty state of the listener.
     listener()->updateState();
 
+    // Update output timestamp.
+    m_outputPosition = outputPosition;
+
     unlock();
   }
 }
@@ -816,6 +822,12 @@ bool BaseAudioContext::isAllowedToStart() const {
   return false;
 }
 
+AudioIOPosition BaseAudioContext::outputPosition() {
+  DCHECK(isMainThread());
+  AutoLocker locker(this);
+  return m_outputPosition;
+}
+
 void BaseAudioContext::rejectPendingResolvers() {
   DCHECK(isMainThread());