Add dataset property to SVGElement interface.

third_party/WebKit/Source/core/svg/SVGElement.idl

Index: third_party/WebKit/Source/core/svg/SVGElement.idl
diff --git a/third_party/WebKit/Source/core/svg/SVGElement.idl b/third_party/WebKit/Source/core/svg/SVGElement.idl
index d8faebbd4ea46206b4e81d3a1eef6ee7044c2bcd..e892a8e41bef813ac94a9df10b1ce5ebf81da6ff 100644
--- a/third_party/WebKit/Source/core/svg/SVGElement.idl
+++ b/third_party/WebKit/Source/core/svg/SVGElement.idl
@@ -24,6 +24,7 @@
 
 interface SVGElement : Element {
     [MeasureAs=SVGClassName] readonly attribute SVGAnimatedString className;
+    [SameObject, PerWorldBindings] readonly attribute DOMStringMap dataset;
     // CSS Object Model (CSSOM)
     // http://dev.w3.org/csswg/cssom/#the-elementcssinlinestyle-interface
     [SameObject, PutForwards=cssText] readonly attribute CSSStyleDeclaration style;