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

Source/core/layout/LayoutGrid.cpp

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 620 matching lines @@
 }
 
 LayoutUnit LayoutGrid::minContentForChild(LayoutBox& child, GridTrackSizingDirection direction, Vector<GridTrack>& columnTracks)
 {
     bool hasOrthogonalWritingMode = child.isHorizontalWritingMode() != isHorizontalWritingMode();
     // FIXME: Properly support orthogonal writing mode.
     if (hasOrthogonalWritingMode)
         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);
     }
 
     return logicalHeightForChild(child, columnTracks);
 }
 
 LayoutUnit LayoutGrid::maxContentForChild(LayoutBox& child, GridTrackSizingDirection direction, Vector<GridTrack>& columnTracks)
 {
     bool hasOrthogonalWritingMode = child.isHorizontalWritingMode() != isHorizontalWritingMode();
     // FIXME: Properly support orthogonal writing mode.
     if (hasOrthogonalWritingMode)
         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);
     }
 
     return logicalHeightForChild(child, columnTracks);
 }
 
 // We're basically using a class instead of a std::pair for two reasons. First of all, accessing gridItem() or
 // coordinate() is much more self-explanatory that using .first or .second members in the pair. Secondly the class
@@ skipping 1078 matching lines @@
     if (isOutOfFlowPositioned())
         return "LayoutGrid (positioned)";
     if (isAnonymous())
         return "LayoutGrid (generated)";
     if (isRelPositioned())
         return "LayoutGrid (relative positioned)";
     return "LayoutGrid";
 }
 
 } // namespace blink