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

Source/modules/mediasource/SourceBufferList.h

Index: Source/modules/mediasource/SourceBufferList.h
diff --git a/Source/modules/mediasource/SourceBufferList.h b/Source/modules/mediasource/SourceBufferList.h
index cbe649c1c2afc464873a495d95dad37489b11d59..3d68f95c029f18269b5432219386ecbf1ef10fb8 100644
--- a/Source/modules/mediasource/SourceBufferList.h
+++ b/Source/modules/mediasource/SourceBufferList.h
@@ -49,8 +49,8 @@ public:
     }
     virtual ~SourceBufferList();
 
-    unsigned long length() const { return m_list.size(); }
-    SourceBuffer* item(unsigned long index) const { return (index < m_list.size()) ? m_list[index].get() : 0; }
+    unsigned length() const { return m_list.size(); }
+    SourceBuffer* item(unsigned index) const { return (index < m_list.size()) ? m_list[index].get() : 0; }
 
     void add(PassRefPtr<SourceBuffer>);
     void remove(SourceBuffer*);