Make DOMArrayBuffer()::byteLength() return unsigned int to match the type of its backing data.

Source/core/dom/DOMArrayBuffer.h

Index: Source/core/dom/DOMArrayBuffer.h
diff --git a/Source/core/dom/DOMArrayBuffer.h b/Source/core/dom/DOMArrayBuffer.h
index c303d071981a14821495f1771b0ef2cedafbc41c..4cf01a27d39e856d1d48f74d06b93516bef64d1b 100644
--- a/Source/core/dom/DOMArrayBuffer.h
+++ b/Source/core/dom/DOMArrayBuffer.h
@@ -38,7 +38,7 @@ public:
 
     const void* data() const { return buffer()->data(); }
     void* data() { return buffer()->data(); }
-    unsigned long byteLength() const { return buffer()->byteLength(); }
+    unsigned byteLength() const { return buffer()->byteLength(); }
     PassRefPtr<DOMArrayBuffer> slice(int begin, int end) const
     {
         return create(buffer()->slice(begin, end));