Implement Automations for PannerNode and AutioListener

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

Index: third_party/WebKit/Source/modules/webaudio/AbstractAudioContext.cpp
diff --git a/third_party/WebKit/Source/modules/webaudio/AbstractAudioContext.cpp b/third_party/WebKit/Source/modules/webaudio/AbstractAudioContext.cpp
index 35fca91ff6d7888f769921a1209d53e3c4b46d77..fcfa28d9c3f55cbcff6d24dc9f2ce5767d40f202 100644
--- a/third_party/WebKit/Source/modules/webaudio/AbstractAudioContext.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/AbstractAudioContext.cpp
@@ -135,10 +135,12 @@ void AbstractAudioContext::initialize()
         return;
 
     FFTFrame::initialize();
-    m_listener = AudioListener::create();
 
     if (m_destinationNode) {
         m_destinationNode->handler().initialize();
+        // The AudioParams in the listener need access to the destination node, so only create the
+        // listener if the destination node exists.
+        m_listener = AudioListener::create(*this);
     }
 }
 
@@ -855,6 +857,9 @@ void AbstractAudioContext::handlePreRenderTasks()
         // Check to see if source nodes can be stopped because the end time has passed.
         handleStoppableSourceNodes();
 
+        // Update the dirty state of the listener.
+        listener()->updateState();
+
         unlock();
     }
 }