use main/cross instead of logical width/height when talking about flow direction

use main/cross instead of logical width/height when talking about flow direction
https://bugs.webkit.org/show_bug.cgi?id=70977

Reviewed by Ojan Vafai.

Flexbox code uses logical in function names to refer to the flow
direction. This is confusing because writing mode also uses logical,
but this is a diffent usage. To avoid confusion, be explicit about
main vs cross axis. Extent is used instead of width/height.

No new tests, just a refactoring.

* rendering/RenderFlexibleBox.cpp:
(WebCore::RenderFlexibleBox::mainAxisLengthForChild):
(WebCore::RenderFlexibleBox::crossAxisLength):
(WebCore::RenderFlexibleBox::setCrossExtent):
(WebCore::RenderFlexibleBox::crossExtentForChild):
(WebCore::RenderFlexibleBox::mainExtentForChild):
(WebCore::RenderFlexibleBox::crossAxisExtent):
(WebCore::RenderFlexibleBox::mainAxisExtent):
(WebCore::RenderFlexibleBox::crossAxisContentExtent):
(WebCore::RenderFlexibleBox::mainAxisContentExtent):
(WebCore::RenderFlexibleBox::crossAxisBorderAndPaddingExtent):
(WebCore::RenderFlexibleBox::crossAxisMarginExtentForChild):
(WebCore::RenderFlexibleBox::flowAwareLocationForChild):
(WebCore::RenderFlexibleBox::setFlowAwareLocationForChild):
(WebCore::RenderFlexibleBox::mainAxisBorderAndPaddingExtentForChild):
(WebCore::RenderFlexibleBox::mainAxisScrollbarExtentForChild):
(WebCore::RenderFlexibleBox::preferredMainAxisContentExtentForFlexItem):
(WebCore::RenderFlexibleBox::layoutInlineDirection):
(WebCore::RenderFlexibleBox::positiveFlexForChild): Since flex only
    matters in the main axis, there's no reason to deambiguate it here.
(WebCore::RenderFlexibleBox::negativeFlexForChild): Ditto.
(WebCore::RenderFlexibleBox::availableAlignmentSpaceForChild): Alignment is always
    in the cross axis direction, so don't include that in the method name.
(WebCore::RenderFlexibleBox::marginBoxAscent):
(WebCore::RenderFlexibleBox::computePreferredMainAxisExtent):
(WebCore::RenderFlexibleBox::runFreeSpaceAllocationAlgorithmInlineDirection):
(WebCore::RenderFlexibleBox::layoutAndPlaceChildrenInlineDirection):
(WebCore::RenderFlexibleBox::adjustAlignmentForChild):  Alignment is always
    in the cross axis direction, so don't include that in the method name.
(WebCore::RenderFlexibleBox::alignChildrenBlockDirection):
* rendering/RenderFlexibleBox.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@98594 268f45cc-cd09-0410-ab3c-d52691b4dbfc