Move handle of HRTFDatabaseLoader to AudioListener.

Source/modules/webaudio/PannerNode.h

Index: Source/modules/webaudio/PannerNode.h
diff --git a/Source/modules/webaudio/PannerNode.h b/Source/modules/webaudio/PannerNode.h
index 840982b387ff8fb881b4ee2d77e03e3a44c4e5c6..5896935ac658c5d42fa387be38273101330b6295 100644
--- a/Source/modules/webaudio/PannerNode.h
+++ b/Source/modules/webaudio/PannerNode.h
@@ -28,7 +28,6 @@
 #include "platform/audio/AudioBus.h"
 #include "platform/audio/Cone.h"
 #include "platform/audio/Distance.h"
-#include "platform/audio/HRTFDatabaseLoader.h"
 #include "platform/audio/Panner.h"
 #include "modules/webaudio/AudioListener.h"
 #include "modules/webaudio/AudioNode.h"
@@ -38,6 +37,8 @@
 
 namespace WebCore {
 
+class HRTFDatabaseLoader;
+
 // PannerNode is an AudioNode with one input and one output.
 // It positions a sound in 3D space, with the exact effect dependent on the panning model.
 // It has a position and an orientation in 3D space which is relative to the position and orientation of the context's AudioListener.
@@ -112,6 +113,7 @@ private:
 
     // AudioContext's listener
     AudioListener* listener();
+    HRTFDatabaseLoader* hrtfDatabaseLoader() { return listener()->hrtfDatabaseLoader(); }
 
     bool setPanningModel(unsigned); // Returns true on success.
     bool setDistanceModel(unsigned); // Returns true on success.
@@ -155,8 +157,6 @@ private:
     float m_cachedDistanceConeGain;
     double m_cachedDopplerRate;
 
-    RefPtr<HRTFDatabaseLoader> m_hrtfDatabaseLoader;
-
     // AudioContext's connection count
     unsigned m_connectionCount;