[CherryPick] Fullscreen element should not share styles with its siblings

[CherryPick] Fullscreen element should not share styles with its siblings

[Title][CherryPick] Fullscreen element should not share styles with its siblings
[Issue] N/A
[Problem] The size of video element is calculated incorrectly sometimes when entering fullscreen.
[Cause] If fullscreen element has sibling, do share the style of sibling element.
[Solution] Cherry picked.
[Cherry-Picker] Seonae Kim

Fullscreen element should not share styles with it's siblings.
https://bugs.webkit.org/show_bug.cgi?id=106888

Reviewed by NOBODY (OOPS!).

Test: fullscreen/full-screen-no-style-sharing.html

* css/StyleResolver.cpp:
(WebCore::StyleResolver::canShareStyleWithElement):

Change-Id: I533bad9411777947546fbf37e0c9bf32f7166593