Fix BaseAudioContext::hasPendingActivity() to make it GCed correctly

third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.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 38 matching lines @@
     void render(AudioBus* sourceBus, AudioBus* destinationBus, size_t numberOfFrames) final;
 
     size_t currentSampleFrame() const { return acquireLoad(&m_currentSampleFrame); }
     double currentTime() const { return currentSampleFrame() / static_cast<double>(sampleRate()); }
 
     virtual unsigned long maxChannelCount() const { return 0; }
 
     virtual void startRendering() = 0;
     virtual void stopRendering() = 0;
 
+    unsigned numberOfConnections() const;
+
 protected:
     // LocalAudioInputProvider allows us to expose an AudioSourceProvider for local/live audio input.
     // If there is local/live audio input, we call set() with the audio input data every render quantum.
     class LocalAudioInputProvider final : public AudioSourceProvider {
     public:
         LocalAudioInputProvider()
             : m_sourceBus(AudioBus::create(2, ProcessingSizeInFrames)) // FIXME: handle non-stereo local input.
         {
         }
 
@@ skipping 12 matching lines @@
                 destinationBus->copyFrom(*m_sourceBus);
         }
 
     private:
         RefPtr<AudioBus> m_sourceBus;
     };
 
     // Counts the number of sample-frames processed by the destination.
     size_t m_currentSampleFrame;
 
+    // Represents the number of incoming connections toward this destination
+    // node. It is updated every render quantum atomically, and it proxies
+    // the connection count for the rendering operation used in
+    // AudioSummingJuntion.
+    unsigned m_numberOfConnections;
+
     LocalAudioInputProvider m_localAudioInputProvider;
 };
 
 class AudioDestinationNode : public AudioNode {
     DEFINE_WRAPPERTYPEINFO();
 public:
     AudioDestinationHandler& audioDestinationHandler() const;
 
     unsigned long maxChannelCount() const;
 
+    bool hasConnection() const;
+
 protected:
     AudioDestinationNode(BaseAudioContext&);
 };
 
 } // namespace blink
 
 #endif // AudioDestinationNode_h