WebAudio: Use references instead of pointers in AudioNodeInput and AudioNodeOutput.

Source/modules/webaudio/AudioNodeInput.h

Index: Source/modules/webaudio/AudioNodeInput.h
diff --git a/Source/modules/webaudio/AudioNodeInput.h b/Source/modules/webaudio/AudioNodeInput.h
index d53bcec7de6b38873133df74b85b0a6e21effbf5..21201c85a5e56b03704e37d6d1756c7d3cae718e 100644
--- a/Source/modules/webaudio/AudioNodeInput.h
+++ b/Source/modules/webaudio/AudioNodeInput.h
@@ -42,24 +42,24 @@ class AudioNodeOutput;
 
 class AudioNodeInput FINAL : public AudioSummingJunction {
 public:
-    static PassOwnPtr<AudioNodeInput> create(AudioNode*);
+    static PassOwnPtr<AudioNodeInput> create(AudioNode&);
 
     // AudioSummingJunction
-    virtual bool canUpdateState() OVERRIDE { return !node()->isMarkedForDeletion(); }
+    virtual bool canUpdateState() OVERRIDE { return !node().isMarkedForDeletion(); }
     virtual void didUpdate() OVERRIDE;
 
     // Can be called from any thread.
-    AudioNode* node() const { return m_node; }
+    AudioNode& node() const { return m_node; }
 
     // Must be called with the context's graph lock.
-    void connect(AudioNodeOutput*);
-    void disconnect(AudioNodeOutput*);
+    void connect(AudioNodeOutput&);
+    void disconnect(AudioNodeOutput&);
 
     // disable() will take the output out of the active connections list and set aside in a disabled list.
     // enable() will put the output back into the active connections list.
     // Must be called with the context's graph lock.
-    void enable(AudioNodeOutput*);
-    void disable(AudioNodeOutput*);
+    void enable(AudioNodeOutput&);
+    void disable(AudioNodeOutput&);
 
     // pull() processes all of the AudioNodes connected to us.
     // In the case of multiple connections it sums the result into an internal summing bus.
@@ -80,9 +80,9 @@ public:
     unsigned numberOfChannels() const;
 
 private:
-    explicit AudioNodeInput(AudioNode*);
+    explicit AudioNodeInput(AudioNode&);
 
-    AudioNode* m_node;
+    AudioNode& m_node;
 
     // m_disabledOutputs contains the AudioNodeOutputs which are disabled (will not be processed) by the audio graph rendering.
     // But, from JavaScript's perspective, these outputs are still connected to us.