DOMException toString is not correct

LayoutTests/svg/dom/SVGLengthList-insertItemBefore-expected.txt

Index: LayoutTests/svg/dom/SVGLengthList-insertItemBefore-expected.txt
diff --git a/LayoutTests/svg/dom/SVGLengthList-insertItemBefore-expected.txt b/LayoutTests/svg/dom/SVGLengthList-insertItemBefore-expected.txt
index f26cf447fd4b850fae59b8965e7dbaac11de3891..c3a5a53b720c822c5cd18dbcb9f74b21d40703f2 100644
--- a/LayoutTests/svg/dom/SVGLengthList-insertItemBefore-expected.txt
+++ b/LayoutTests/svg/dom/SVGLengthList-insertItemBefore-expected.txt
@@ -21,7 +21,7 @@ PASS text1.x.baseVal.numberOfItems is 3
 PASS text1.x.baseVal.getItem(0).value is 500
 PASS text1.x.baseVal.getItem(1).value is 1000
 PASS text1.x.baseVal.getItem(2).value is 1500
-PASS text1.x.baseVal.getItem(3) threw exception Error: IndexSizeError: DOM Exception 1.
+PASS text1.x.baseVal.getItem(3) threw exception IndexSizeError: Index or size was negative, or greater than the allowed value..
 
 Insert item 'newLength1' at the end of the list, by using a large index
 PASS text1.x.baseVal.insertItemBefore(newLength1, 1000) is newLength1
@@ -30,7 +30,7 @@ PASS text1.x.baseVal.getItem(0).value is 500
 PASS text1.x.baseVal.getItem(1).value is 1000
 PASS text1.x.baseVal.getItem(2).value is 1500
 PASS text1.x.baseVal.getItem(3).value is 50
-PASS text1.x.baseVal.getItem(4) threw exception Error: IndexSizeError: DOM Exception 1.
+PASS text1.x.baseVal.getItem(4) threw exception IndexSizeError: Index or size was negative, or greater than the allowed value..
 
 Storing getItem(0/1/2) in local variables
 
@@ -42,7 +42,7 @@ PASS text1.x.baseVal.getItem(1).value is 500
 PASS text1.x.baseVal.getItem(2).value is 1000
 PASS text1.x.baseVal.getItem(3).value is 1500
 PASS text1.x.baseVal.getItem(4).value is 50
-PASS text1.x.baseVal.getItem(5) threw exception Error: IndexSizeError: DOM Exception 1.
+PASS text1.x.baseVal.getItem(5) threw exception IndexSizeError: Index or size was negative, or greater than the allowed value..
 
 Assure that previously saved wrappers still show the old values
 PASS item0.value is 500
@@ -59,7 +59,7 @@ PASS text1.x.baseVal.getItem(2).value is 150
 PASS text1.x.baseVal.getItem(3).value is 1000
 PASS text1.x.baseVal.getItem(4).value is 1500
 PASS text1.x.baseVal.getItem(5).value is 50
-PASS text1.x.baseVal.getItem(6) threw exception Error: IndexSizeError: DOM Exception 1.
+PASS text1.x.baseVal.getItem(6) threw exception IndexSizeError: Index or size was negative, or greater than the allowed value..
 
 Insert item 'newLength3' at position=1, between '100' and '500', remove it from the old position=2 afterwards.
 PASS text1.x.baseVal.insertItemBefore(newLength3, 1) is newLength3
@@ -70,7 +70,7 @@ PASS text1.x.baseVal.getItem(2).value is 500
 PASS text1.x.baseVal.getItem(3).value is 1000
 PASS text1.x.baseVal.getItem(4).value is 1500
 PASS text1.x.baseVal.getItem(5).value is 50
-PASS text1.x.baseVal.getItem(6) threw exception Error: IndexSizeError: DOM Exception 1.
+PASS text1.x.baseVal.getItem(6) threw exception IndexSizeError: Index or size was negative, or greater than the allowed value..
 
 Insert item 'newLength3' at position=0, before '100', remove it from the old position=5 afterwards.
 PASS text1.x.baseVal.insertItemBefore(newLength1, 0) is newLength1
@@ -81,7 +81,7 @@ PASS text1.x.baseVal.getItem(2).value is 150
 PASS text1.x.baseVal.getItem(3).value is 500
 PASS text1.x.baseVal.getItem(4).value is 1000
 PASS text1.x.baseVal.getItem(5).value is 1500
-PASS text1.x.baseVal.getItem(6) threw exception Error: IndexSizeError: DOM Exception 1.
+PASS text1.x.baseVal.getItem(6) threw exception IndexSizeError: Index or size was negative, or greater than the allowed value..
 
 The test passes if you only see 'PASS' messages, and both text elements on top look the same