Document.elementFromPoint() should take page scroll into consideration

Reviewed by Anders Carlsson.

Test: fast/dom/elementFromPoint-relative-to-viewport.html

* dom/Document.cpp:
(WebCore::Document::elementFromPoint):
(WebCore::Document::caretRangeFromPoint):

LayoutTests: Test for https://bugs.webkit.org/show_bug.cgi?id=29219
Document.elementFromPoint() should take page scroll into consideration

Reviewed by Anders Carlsson.

* fast/dom/elementFromPoint-relative-to-viewport-expected.txt: Added.
* fast/dom/elementFromPoint-relative-to-viewport.html: Added.
* fast/events/offsetX-offsetY.html: Change to use clientX/Y instead of pageX/Y.
* fast/forms/slider-transformed.html: Ditto.
* fast/forms/slider-zoomed.html: Ditto.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@48334 268f45cc-cd09-0410-ab3c-d52691b4dbfc