Floated flexboxes render as regular RenderBlocks

Floated flexboxes render as regular RenderBlocks
https://bugs.webkit.org/show_bug.cgi?id=77909

Reviewed by Eric Seidel.

Source/WebCore:

Add grid/flexbox cases to adjusting the display of floated/positioned
elements. Also, move this logic into a switch statement. This makes
the code more readable and gives compile warnings when new display types
are added that aren't handled here.

Test: css3/flexbox/floated-flexbox.html

* css/CSSStyleSelector.cpp:
(WebCore::adjustDisplay):
(WebCore):
(WebCore::CSSStyleSelector::adjustRenderStyle):

LayoutTests:

* css3/flexbox/floated-flexbox-expected.txt: Added.
* css3/flexbox/floated-flexbox.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@107112 268f45cc-cd09-0410-ab3c-d52691b4dbfc