use CanvasWindingRule enumeration in CanvasRenderingContext2D.idl
https://bugs.webkit.org/show_bug.cgi?id=113456

Patch by Arnaud Renevier <a.renevier@sisa.samsung.com> on 2013-03-28
Reviewed by Kentaro Hara.

Source/WebCore:

Use enum CanvasWindingRule type instead of DOMString for winding
arguments when needed. Changed methods are: fill, stroke and isPointInPath.

Test: fast/canvas/winding-enumeration.html

* html/canvas/CanvasRenderingContext2D.idl:

LayoutTests:

When calling methods accepting a CanvasWindingRule with an invalid
string, check that a TypeError is thrown.

* fast/canvas/winding-enumeration-expected.txt: Added.
* fast/canvas/winding-enumeration.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147133 268f45cc-cd09-0410-ab3c-d52691b4dbfc