Move handle of HRTFDatabaseLoader to AudioListener.

Source/modules/webaudio/PannerNode.cpp

Index: Source/modules/webaudio/PannerNode.cpp
diff --git a/Source/modules/webaudio/PannerNode.cpp b/Source/modules/webaudio/PannerNode.cpp
index 029c73cf16cbee3b6c7f1bd380557f004719b5ec..7783013acc746ad74057e97f213aa03e4c351063 100644
--- a/Source/modules/webaudio/PannerNode.cpp
+++ b/Source/modules/webaudio/PannerNode.cpp
@@ -29,6 +29,7 @@
 #include "modules/webaudio/PannerNode.h"
 
 #include "core/dom/ExecutionContext.h"
+#include "platform/audio/HRTFDatabaseLoader.h"
 #include "platform/audio/HRTFPanner.h"
 #include "modules/webaudio/AudioBufferSourceNode.h"
 #include "modules/webaudio/AudioContext.h"
@@ -65,7 +66,8 @@ PannerNode::PannerNode(AudioContext* context, float sampleRate)
 {
     // Load the HRTF database asynchronously so we don't block the Javascript thread while creating the HRTF database.
     // The HRTF panner will return zeroes until the database is loaded.
-    m_hrtfDatabaseLoader = HRTFDatabaseLoader::createAndLoadAsynchronouslyIfNecessary(context->sampleRate());
+    RefPtrWillBeRawPtr<HRTFDatabaseLoader> loader = HRTFDatabaseLoader::createAndLoadAsynchronouslyIfNecessary(context->sampleRate());

[tkent, 2014/07/16 23:32:25]

RefPtrWillBeRawPtr should be RefPtr.

[KhNo, 2014/07/17 16:23:17]

Done.

+    listener()->setHRTFDatabaseLoader(loader.release());

[Raymond Toy, 2014/07/16 16:35:38]

Per the comment above, should we check that listener hasn't already set the
handle?

Maybe we should just do something like

listener()->createAndLoadAsynchronouslyIfNecessary(context->sampleRate())

and let listener take care of setting the handle only once? 

But it seems that HRTFDatabaseLoader::createAsynchronouslyIfNecessary returns
the same loader object if it's already been loaded.

[KhNo, 2014/07/17 16:23:17]

Yes, we must. Thanks.
I think your proposal is much better handing on listener.
Inside listener, it will be care of it.

 
     ScriptWrappable::init(this);
     addInput(adoptPtr(new AudioNodeInput(this)));
@@ -125,9 +127,9 @@ void PannerNode::process(size_t framesToProcess)
 
     if (tryLocker.locked() && tryListenerLocker.locked()) {
         // HRTFDatabase should be loaded before proceeding for offline audio context when the panning model is HRTF.
-        if (m_panningModel == Panner::PanningModelHRTF && !m_hrtfDatabaseLoader->isLoaded()) {
+        if (m_panningModel == Panner::PanningModelHRTF && !hrtfDatabaseLoader()->isLoaded()) {
             if (context()->isOfflineContext()) {
-                m_hrtfDatabaseLoader->waitForLoaderThreadCompletion();
+                hrtfDatabaseLoader()->waitForLoaderThreadCompletion();
             } else {
                 destination->zero();
                 return;
@@ -162,7 +164,7 @@ void PannerNode::initialize()
     if (isInitialized())
         return;
 
-    m_panner = Panner::create(m_panningModel, sampleRate(), m_hrtfDatabaseLoader.get());
+    m_panner = Panner::create(m_panningModel, sampleRate(), hrtfDatabaseLoader());
     listener()->addPanner(this);
 
     AudioNode::initialize();
@@ -213,7 +215,7 @@ bool PannerNode::setPanningModel(unsigned model)
         if (!m_panner.get() || model != m_panningModel) {
             // This synchronizes with process().
             MutexLocker processLocker(m_processLock);
-            OwnPtr<Panner> newPanner = Panner::create(model, sampleRate(), m_hrtfDatabaseLoader.get());
+            OwnPtr<Panner> newPanner = Panner::create(model, sampleRate(), hrtfDatabaseLoader());
             m_panner = newPanner.release();
             m_panningModel = model;
         }