Use "int" instead of "long" for bindings where the WebIDL uses "long".

Source/modules/webaudio/AudioContext.h

Index: Source/modules/webaudio/AudioContext.h
diff --git a/Source/modules/webaudio/AudioContext.h b/Source/modules/webaudio/AudioContext.h
index 09890bafcc05c7c6b153814fcdcccff5c4ea67c0..ed9b76b54d48ed8e1b9176f8f4f1df22a7c68dd0 100644
--- a/Source/modules/webaudio/AudioContext.h
+++ b/Source/modules/webaudio/AudioContext.h
@@ -103,7 +103,8 @@ public:
     size_t currentSampleFrame() const { return m_destinationNode->currentSampleFrame(); }
     double currentTime() const { return m_destinationNode->currentTime(); }
     float sampleRate() const { return m_destinationNode->sampleRate(); }
-    unsigned long activeSourceCount() const { return static_cast<unsigned long>(m_activeSourceCount); }
+    // FIXME: Is this cast safe (what if m_activeSourceCount is negative...)
+    unsigned activeSourceCount() const { return static_cast<unsigned>(m_activeSourceCount); }
 
     void incrementActiveSourceCount();
     void decrementActiveSourceCount();