Use null for default value of event handler attributes in XMLHttpRequest....

third_party/WebKit/WebCore/bindings/v8/custom/V8XMLHttpRequestUploadCustom.cpp

Index: third_party/WebKit/WebCore/bindings/v8/custom/V8XMLHttpRequestUploadCustom.cpp
===================================================================
--- third_party/WebKit/WebCore/bindings/v8/custom/V8XMLHttpRequestUploadCustom.cpp	(revision 13799)
+++ third_party/WebKit/WebCore/bindings/v8/custom/V8XMLHttpRequestUploadCustom.cpp	(working copy)
@@ -52,7 +52,7 @@
         v8::Local<v8::Object> v8Listener = listener->getListenerObject();
         return v8Listener;
     }
-    return v8::Undefined();
+    return v8::Null();
 }
 
 ACCESSOR_SETTER(XMLHttpRequestUploadOnabort)
@@ -91,7 +91,7 @@
         v8::Local<v8::Object> v8Listener = listener->getListenerObject();
         return v8Listener;
     }
-    return v8::Undefined();
+    return v8::Null();
 }
 
 ACCESSOR_SETTER(XMLHttpRequestUploadOnerror)
@@ -130,7 +130,7 @@
         v8::Local<v8::Object> v8Listener = listener->getListenerObject();
         return v8Listener;
     }
-    return v8::Undefined();
+    return v8::Null();
 }
 
 ACCESSOR_SETTER(XMLHttpRequestUploadOnload)
@@ -169,7 +169,7 @@
         v8::Local<v8::Object> v8Listener = listener->getListenerObject();
         return v8Listener;
     }
-    return v8::Undefined();
+    return v8::Null();
 }
 
 ACCESSOR_SETTER(XMLHttpRequestUploadOnloadstart)
@@ -208,7 +208,7 @@
         v8::Local<v8::Object> v8Listener = listener->getListenerObject();
         return v8Listener;
     }
-    return v8::Undefined();
+    return v8::Null();
 }
 
 ACCESSOR_SETTER(XMLHttpRequestUploadOnprogress)