[Oilpan] Prepare full definition of classes before using Member

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

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 115 matching lines @@
     float sampleRate() const { return m_destinationNode ? m_destinationNode->handler().sampleRate() : 0; }
 
     String state() const;
     AudioContextState contextState() const { return m_contextState; }
 
     AudioBuffer* createBuffer(unsigned numberOfChannels, size_t numberOfFrames, float sampleRate, ExceptionState&);
 
     // Asynchronous audio file data decoding.
     void decodeAudioData(DOMArrayBuffer*, AudioBufferCallback*, AudioBufferCallback*, ExceptionState&);
 
-    AudioListener* listener() { return m_listener.get(); }
+    AudioListener* listener() const;
 
     virtual bool hasRealtimeConstraint() = 0;
 
     // The AudioNode create methods are called on the main thread (from JavaScript).
     AudioBufferSourceNode* createBufferSource(ExceptionState&);
     MediaElementAudioSourceNode* createMediaElementSource(HTMLMediaElement*, ExceptionState&);
     MediaStreamAudioSourceNode* createMediaStreamSource(MediaStream*, ExceptionState&);
     MediaStreamAudioDestinationNode* createMediaStreamDestination(ExceptionState&);
     GainNode* createGain(ExceptionState&);
     BiquadFilterNode* createBiquadFilter(ExceptionState&);
@@ skipping 170 matching lines @@
     void handleStoppableSourceNodes();
 
     // This is considering 32 is large enough for multiple channels audio.
     // It is somewhat arbitrary and could be increased if necessary.
     enum { MaxNumberOfChannels = 32 };
 };
 
 } // namespace blink
 
 #endif // AbstractAudioContext_h