[CSSGridLayout] Skip items spanning flex tracks in track sizing algo

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 a459c51506629a0765ae64109fd4ab4de0e1b92e..886d6d4f15e954804fd43d5c303b74b015ff1518 100644
--- a/Source/core/rendering/RenderGrid.cpp
+++ b/Source/core/rendering/RenderGrid.cpp
@@ -682,6 +682,7 @@ public:
 
     RenderBox& gridItem() const { return *m_gridItem; }
     GridCoordinate coordinate() const { return m_coordinate; }
+    bool spansMultipleTracks() const { return m_span > 1; }
 
     bool operator<(const GridItemWithSpan other) const { return m_span < other.m_span; }
 
@@ -712,6 +713,21 @@ struct VectorTraits<blink::GridItemWithSpan> : SimpleClassVectorTraits<blink::Gr
 
 namespace blink {
 
+bool RenderGrid::itemSpansFlexibleSizedTracks(const GridItemWithSpan& gridItemWithSpan, GridTrackSizingDirection direction) const
+{
+    const GridCoordinate coordinate = gridItemWithSpan.coordinate();
+    const GridResolvedPosition initialTrackPosition = (direction == ForColumns) ? coordinate.columns.resolvedInitialPosition : coordinate.rows.resolvedInitialPosition;
+    const GridResolvedPosition finalTrackPosition = (direction == ForColumns) ? coordinate.columns.resolvedFinalPosition : coordinate.rows.resolvedFinalPosition;
+
+    for (GridResolvedPosition trackPosition = initialTrackPosition; trackPosition <= finalTrackPosition; ++trackPosition) {
+        const GridTrackSize& trackSize = gridTrackSize(direction, trackPosition.toInt());

[Julien - ping for review, 2014/10/15 16:04:58]

Too bad we have this call, else we could have moved this function to
GridItemWithSpan.

[svillar, 2014/10/16 06:36:30]

Acknowledged.

+        if (trackSize.minTrackBreadth().isFlex() || trackSize.maxTrackBreadth().isFlex())
+            return true;
+    }
+
+    return false;
+}
+
 void RenderGrid::resolveContentBasedTrackSizingFunctions(GridTrackSizingDirection direction, GridSizingData& sizingData, LayoutUnit& availableLogicalSpace)
 {
     sizingData.itemsSortedByIncreasingSpan.shrink(0);
@@ -728,8 +744,11 @@ void RenderGrid::resolveContentBasedTrackSizingFunctions(GridTrackSizingDirectio
 
     Vector<GridItemWithSpan>::iterator end = sizingData.itemsSortedByIncreasingSpan.end();
     for (Vector<GridItemWithSpan>::iterator it = sizingData.itemsSortedByIncreasingSpan.begin(); it != end; ++it) {
-        // FIXME: do not consider items with a span > 1 that span a track with a flexible sizing function.
         GridItemWithSpan itemWithSpan = *it;
+        // We should not consider items spanning more than one track that span tracks with flexible sizing functions.
+        if (itemWithSpan.spansMultipleTracks() && itemSpansFlexibleSizedTracks(itemWithSpan, direction))
+            continue;
+
         resolveContentBasedTrackSizingFunctionsForItems(direction, sizingData, itemWithSpan, &GridTrackSize::hasMinOrMaxContentMinTrackBreadth, &RenderGrid::minContentForChild, &GridTrack::usedBreadth, &GridTrack::growUsedBreadth);
         resolveContentBasedTrackSizingFunctionsForItems(direction, sizingData, itemWithSpan, &GridTrackSize::hasMaxContentMinTrackBreadth, &RenderGrid::maxContentForChild, &GridTrack::usedBreadth, &GridTrack::growUsedBreadth);
         resolveContentBasedTrackSizingFunctionsForItems(direction, sizingData, itemWithSpan, &GridTrackSize::hasMinOrMaxContentMaxTrackBreadth, &RenderGrid::minContentForChild, &GridTrack::maxBreadthIfNotInfinite, &GridTrack::growMaxBreadth);