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

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

Index: third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h
diff --git a/third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h b/third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h
index a2c419a469b5e4eb25eeb45044ca653c52585bbc..40758cb907402dce56116c4d1411719d36089846 100644
--- a/third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h
+++ b/third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.h
@@ -56,6 +56,8 @@ public:
     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.
@@ -88,6 +90,12 @@ protected:
     // 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;
 };
 
@@ -98,6 +106,8 @@ public:
 
     unsigned long maxChannelCount() const;
 
+    bool hasConnection() const;
+
 protected:
     AudioDestinationNode(BaseAudioContext&);
 };