[CSS Grid Layout] Use Render methods, rather than style, to determine shrink-to-fit behavior

Source/core/rendering/RenderGrid.cpp

Index: Source/core/rendering/RenderGrid.cpp
diff --git a/Source/core/rendering/RenderGrid.cpp b/Source/core/rendering/RenderGrid.cpp
index 89119b8a93c5afe8f4e1fed5734a5caf7629ab35..74247ff6924411df5758dae7342ba8d59d8373a1 100644
--- a/Source/core/rendering/RenderGrid.cpp
+++ b/Source/core/rendering/RenderGrid.cpp
@@ -341,9 +341,9 @@ void RenderGrid::computeUsedBreadthOfGridTracks(GridTrackSizingDirection directi
     computeUsedBreadthOfGridTracks(direction, sizingData, availableLogicalSpace);
 }
 
-static bool gridElementIsShrinkToFit(const RenderStyle& style)
+bool RenderGrid::gridElementIsShrinkToFit()
 {
-    return style.isFloating() || style.position() == AbsolutePosition;
+    return isFloatingOrOutOfFlowPositioned();

[Julien - ping for review, 2014/02/26 22:43:43]

Are fixed elements also shrink-to-fit? (this will return true for fixed elements
so it is worth adding some testing for that).

 }
 
 void RenderGrid::computeUsedBreadthOfGridTracks(GridTrackSizingDirection direction, GridSizingData& sizingData, LayoutUnit& availableLogicalSpace)
@@ -379,7 +379,7 @@ void RenderGrid::computeUsedBreadthOfGridTracks(GridTrackSizingDirection directi
         availableLogicalSpace -= tracks[i].m_usedBreadth;
     }
 
-    const bool hasUndefinedRemainingSpace = (direction == ForRows) ? style()->logicalHeight().isAuto() : gridElementIsShrinkToFit(*style());
+    const bool hasUndefinedRemainingSpace = (direction == ForRows) ? style()->logicalHeight().isAuto() : gridElementIsShrinkToFit();
 
     if (!hasUndefinedRemainingSpace && availableLogicalSpace <= 0)
         return;