Update Element API for CSSOM smooth scrolling to match the spec

Source/core/dom/Element.idl

Index: Source/core/dom/Element.idl
diff --git a/Source/core/dom/Element.idl b/Source/core/dom/Element.idl
index 121f7e1e5078da87d1029869e505cb27825d80e2..267d22e69198fb7c20727d0c714fb90b23af4082 100644
--- a/Source/core/dom/Element.idl
+++ b/Source/core/dom/Element.idl
@@ -69,15 +69,18 @@ interface Element : Node {
     readonly attribute long clientWidth;
     readonly attribute long clientHeight;
 
-    // FIXME: should be:
-    // attribute (Dictionary or double) scrollLeft;
-    // attribute (Dictionary or double) scrollTop;
-    // http://crbug.com/240176
-    [Custom=Setter] attribute double scrollLeft;
-    [Custom=Setter] attribute double scrollTop;

[Ian Vollick, 2014/12/08 16:35:23]

Cool. It's really nice that you were able to ditch the custom setter.

+    attribute double scrollLeft;
+    attribute double scrollTop;
     readonly attribute long scrollWidth;
     readonly attribute long scrollHeight;
 
+    [RuntimeEnabled=CSSOMSmoothScroll] void scroll(double x, double y);
+    [RuntimeEnabled=CSSOMSmoothScroll] void scroll([Default=Undefined] optional ScrollToOptions scrollToOptions);

[Jens Widell, 2014/12/08 16:19:07]

[Default=Undefined] has no effect on optional dictionary type arguments. (The
effect it has on other types of arguments is implied for dictionary type
arguments.)

So, since it's just noise, remove it?

[ajuma, 2014/12/08 18:34:13]

Done.

+    [RuntimeEnabled=CSSOMSmoothScroll] void scrollTo(double x, double y);
+    [RuntimeEnabled=CSSOMSmoothScroll] void scrollTo([Default=Undefined] optional ScrollToOptions scrollToOptions);
+    [RuntimeEnabled=CSSOMSmoothScroll] void scrollBy(double x, double y);
+    [RuntimeEnabled=CSSOMSmoothScroll] void scrollBy([Default=Undefined] optional ScrollToOptions scrollToOptions);
+
     void focus();
     void blur();
     void scrollIntoView(optional boolean alignWithTop);