[DO NOT SUBMIT] AudioWorklet FS2: audio thread

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

Index: third_party/WebKit/Source/modules/webaudio/OfflineAudioDestinationNode.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/OfflineAudioDestinationNode.cpp b/third_party/WebKit/Source/modules/webaudio/OfflineAudioDestinationNode.cpp
index f82b93abecc2c78ca57ac9a6d0d8796364db2f99..2363ae5cbf11d7ea48d39286fd470b0e4ee00031 100644
--- a/third_party/WebKit/Source/modules/webaudio/OfflineAudioDestinationNode.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/OfflineAudioDestinationNode.cpp
@@ -163,9 +163,9 @@ void OfflineAudioDestinationHandler::doOfflineRendering()
     // Reset the suspend flag.
     m_shouldSuspend = false;
 
-    // If there is more to process and there is no suspension at the moment,
-    // do continue to render quanta. Then calling OfflineAudioContext.resume() will pick up
-    // the render loop again from where it was suspended.
+    // If there is more to process and there is no suspension at the moment, do
+    // continue to render quanta. Then calling OfflineAudioContext.resume() will
+    // pick up the render loop again from where it was suspended.
     while (m_framesToProcess > 0 && !m_shouldSuspend) {
 
         // Suspend the rendering and update m_shouldSuspend if a scheduled
@@ -271,23 +271,27 @@ bool OfflineAudioDestinationHandler::renderIfNotSuspended(AudioBus* sourceBus, A
         return true;
     }
 
-    // Prepare the local audio input provider for this render quantum.
-    if (sourceBus)
-        m_localAudioInputProvider.set(sourceBus);
+    // TODO(hongchan): OfflineAudioContext does not care about the live input.
+    // Remove this.
+    // if (sourceBus)
+    //     m_localAudioInputProvider.setSourceBus(sourceBus);
 
     ASSERT(numberOfInputs() >= 1);
     if (numberOfInputs() < 1) {
         destinationBus->zero();
         return false;
     }
+
     // This will cause the node(s) connected to us to process, which in turn will pull on their input(s),
     // all the way backwards through the rendering graph.
     AudioBus* renderedBus = input(0).pull(destinationBus, numberOfFrames);
 
+    // TODO(hongchan): this logic should be a part of AudioNodeInput::pull().
     if (!renderedBus) {
         destinationBus->zero();
     } else if (renderedBus != destinationBus) {
-        // in-place processing was not possible - so copy
+        // If the destination node has multiple inputs, in-place processing is
+        // not possible. Thus the explicit copy is necessary.
         destinationBus->copyFrom(*renderedBus);
     }