[CSS Grid Layout] Determine definite/indefinite size properly in nested grids

Source/core/layout/LayoutGrid.cpp

Index: Source/core/layout/LayoutGrid.cpp
diff --git a/Source/core/layout/LayoutGrid.cpp b/Source/core/layout/LayoutGrid.cpp
index add685ab608673b919360b1109411e75028b78bd..41a747ab8635eb6a17de6a39ce6e49e655124752 100644
--- a/Source/core/layout/LayoutGrid.cpp
+++ b/Source/core/layout/LayoutGrid.cpp
@@ -638,6 +638,11 @@ LayoutUnit LayoutGrid::minContentForChild(LayoutBox& child, GridTrackSizingDirec
         return 0;
 
     if (direction == ForColumns) {
+        // If |child| has a percentage logical width, we shouldn't let it override its intrinsic width, which is
+        // what we are interested in here. Thus we need to set the override logical width to -1 (no possible resolution).
+        if (child.style()->logicalWidth().isPercent())
+            child.setOverrideContainingBlockContentLogicalWidth(-1);

[Julien - ping for review, 2015/02/27 02:07:03]

Our need to change the override constantly means that we won't be able to skip
any of those forced relayouts. It's not a comment on your change specifically
but on something that's deeper rooted in our code.

[Manuel Rego, 2015/02/27 08:48:50]

I agree. We should try to find a best alternative at some point.

+

[Manuel Rego, 2015/02/25 16:57:59]

In addition to previous changes I needed to add this here
(similar to what we have in logicalHeightForChild()).

         // FIXME: It's unclear if we should return the intrinsic width or the preferred width.
         // See http://lists.w3.org/Archives/Public/www-style/2013Jan/0245.html
         return child.minPreferredLogicalWidth() + marginIntrinsicLogicalWidthForChild(child);
@@ -654,6 +659,11 @@ LayoutUnit LayoutGrid::maxContentForChild(LayoutBox& child, GridTrackSizingDirec
         return LayoutUnit();
 
     if (direction == ForColumns) {
+        // If |child| has a percentage logical width, we shouldn't let it override its intrinsic width, which is
+        // what we are interested in here. Thus we need to set the override logical width to -1 (no possible resolution).
+        if (child.style()->logicalWidth().isPercent())
+            child.setOverrideContainingBlockContentLogicalWidth(-1);
+
         // FIXME: It's unclear if we should return the intrinsic width or the preferred width.
         // See http://lists.w3.org/Archives/Public/www-style/2013Jan/0245.html
         return child.maxPreferredLogicalWidth() + marginIntrinsicLogicalWidthForChild(child);