implement display: -webkit-inline-flexbox

implement display: -webkit-inline-flexbox
https://bugs.webkit.org/show_bug.cgi?id=77772

Reviewed by David Hyatt.

Source/WebCore:

Tests: css3/flexbox/inline-flexbox-expected.html
       css3/flexbox/inline-flexbox.html

* rendering/style/RenderStyle.h:
-Add INLINE_FLEXBOX to the list of replaced display types.
-Restructure the isDisplayInline methods to avoid code duplication.

LayoutTests:

* css3/flexbox/inline-flexbox-expected.html: Added.
* css3/flexbox/inline-flexbox.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@109014 268f45cc-cd09-0410-ab3c-d52691b4dbfc