[CSS Grid Layout] Simplify the interface of GridResolvedPosition

[CSS Grid Layout] Simplify the interface of GridResolvedPosition
https://bugs.webkit.org/show_bug.cgi?id=139077

Reviewed by Darin Adler.

The interface of GridResolvedPosition is full of static methods
that are used only internally, we should not expose them.

Apart from that resolveGridPositionsFromStyle() do always return
a valid GridSpan from now on meaning that the caller has to ensure
that the resolution does not require running the auto-placement
algorithm. A new class called GridUnresolvedSpan was added for
that purpose.

No new tests as this is a refactoring.

* rendering/RenderGrid.cpp:
(WebCore::RenderGrid::placeItemsOnGrid):
(WebCore::RenderGrid::populateExplicitGridAndOrderIterator):
(WebCore::RenderGrid::placeSpecifiedMajorAxisItemsOnGrid):
(WebCore::RenderGrid::placeAutoMajorAxisItemOnGrid):
* rendering/style/GridPosition.h:
* rendering/style/GridResolvedPosition.cpp:
(WebCore::gridLinesForSide):
(WebCore::implicitNamedGridLineForSide):
(WebCore::isNonExistentNamedLineOrArea):
(WebCore::GridUnresolvedSpan::requiresAutoPlacement):
(WebCore::GridUnresolvedSpan::adjustGridPositionsFromStyle):
(WebCore::adjustGridPositionForRowEndColumnEndSide):
(WebCore::adjustGridPositionForSide):
(WebCore::resolveNamedGridLinePositionFromStyle):
(WebCore::firstNamedGridLineBeforePosition):
(WebCore::resolveRowStartColumnStartNamedGridLinePositionAgainstOppositePosition):
(WebCore::resolveRowEndColumnEndNamedGridLinePositionAgainstOppositePosition):
(WebCore::resolveNamedGridLinePositionAgainstOppositePosition):
(WebCore::resolveGridPositionAgainstOppositePosition):
(WebCore::GridResolvedPosition::resolveGridPositionsFromAutoPlacementPosition):
(WebCore::resolveGridPositionFromStyle):
(WebCore::GridResolvedPosition::GridResolvedPosition):
(WebCore::GridResolvedPosition::unresolvedSpanFromStyle):
(WebCore::GridResolvedPosition::resolveGridPositionsFromStyle):
(WebCore::GridResolvedPosition::adjustGridPositionsFromStyle): Deleted.
(WebCore::GridResolvedPosition::resolveNamedGridLinePositionFromStyle): Deleted.
(WebCore::GridResolvedPosition::resolveGridPositionFromStyle): Deleted.
(WebCore::GridResolvedPosition::resolveGridPositionAgainstOppositePosition): Deleted.
(WebCore::GridResolvedPosition::resolveNamedGridLinePositionAgainstOppositePosition): Deleted.
(WebCore::GridResolvedPosition::resolveRowStartColumnStartNamedGridLinePositionAgainstOppositePosition): Deleted.
(WebCore::GridResolvedPosition::resolveRowEndColumnEndNamedGridLinePositionAgainstOppositePosition): Deleted.
* rendering/style/GridResolvedPosition.h:
(WebCore::GridUnresolvedSpan::GridUnresolvedSpan): New class.
(WebCore::GridUnresolvedSpan::initialPosition):
(WebCore::GridUnresolvedSpan::finalPosition):
(WebCore::GridUnresolvedSpan::initialPositionSide):
(WebCore::GridUnresolvedSpan::finalPositionSide):
(WebCore::GridResolvedPosition::adjustGridPositionForRowEndColumnEndSide): Deleted.
(WebCore::GridResolvedPosition::adjustGridPositionForSide): Deleted.
(WebCore::GridResolvedPosition::GridResolvedPosition): Deleted.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@185059 268f45cc-cd09-0410-ab3c-d52691b4dbfc