[css-grid] Remove the 2x computation of row sizes w/ indefinite heights

third_party/WebKit/Source/core/layout/LayoutGrid.cpp

Index: third_party/WebKit/Source/core/layout/LayoutGrid.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
index a34960d16c5496f9514bb0a222be58472a526579..a4a1cb96327215aeaa545ba88d61001c9e98a5b6 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -453,7 +453,6 @@ void LayoutGrid::layoutBlock(bool relayoutChildren)
         LayoutSize previousSize = size();
 
         updateLogicalWidth();
-        bool logicalHeightWasIndefinite = !hasDefiniteLogicalHeight();
 
         TextAutosizer::LayoutScope textAutosizerLayoutScope(this, &layoutScope);
 
@@ -475,7 +474,7 @@ void LayoutGrid::layoutBlock(bool relayoutChildren)
 
         // 2- Next, the track sizing algorithm resolves the sizes of the grid rows, using the
         // grid column sizes calculated in the previous step.
-        if (logicalHeightWasIndefinite)
+        if (!hasDefiniteLogicalHeight())
             computeIntrinsicLogicalHeight(sizingData);
         else
             computeTrackSizesForDirection(ForRows, sizingData, availableLogicalHeight(ExcludeMarginBorderPadding));
@@ -484,16 +483,10 @@ void LayoutGrid::layoutBlock(bool relayoutChildren)
         LayoutUnit oldClientAfterEdge = clientLogicalBottom();
         updateLogicalHeight();
 
-        // The above call might have changed the grid's logical height depending on min|max height restrictions.
-        // Update the sizes of the rows whose size depends on the logical height (also on definite|indefinite sizes).
-        LayoutUnit availableSpaceForRows = contentLogicalHeight();
-        if (logicalHeightWasIndefinite)
-            computeTrackSizesForDirection(ForRows, sizingData, availableSpaceForRows);
-
         // 3- If the min-content contribution of any grid items have changed based on the row
         // sizes calculated in step 2, steps 1 and 2 are repeated with the new min-content
         // contribution (once only).
-        repeatTracksSizingIfNeeded(sizingData, availableSpaceForColumns, availableSpaceForRows);
+        repeatTracksSizingIfNeeded(sizingData, availableSpaceForColumns, contentLogicalHeight());
 
         // Grid container should have the minimum height of a line if it's editable. That doesn't affect track sizing though.
         if (hasLineIfEmpty())
@@ -623,6 +616,7 @@ void LayoutGrid::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, Layo
 
 void LayoutGrid::computeIntrinsicLogicalHeight(GridSizingData& sizingData)
 {
+    DCHECK(sizingData.isValidTransition(ForRows));
     ASSERT(tracksAreWiderThanMinTrackBreadth(ForColumns, sizingData));
     sizingData.setAvailableSpace(LayoutUnit());
     sizingData.freeSpace(ForRows) = LayoutUnit();
@@ -634,6 +628,7 @@ void LayoutGrid::computeIntrinsicLogicalHeight(GridSizingData& sizingData)
     m_maxContentHeight += totalGuttersSize;
 
     ASSERT(tracksAreWiderThanMinTrackBreadth(ForRows, sizingData));
+    sizingData.nextState();

[jfernandez, 2016/09/14 21:54:46]

It's a bit confusing/peculiar that intrinsic size computation became part of the
regular track sizing algorithm. 

 }
 
 LayoutUnit LayoutGrid::computeIntrinsicLogicalContentHeightUsing(const Length& logicalHeightLength, LayoutUnit intrinsicContentHeight, LayoutUnit borderAndPadding) const
@@ -1895,6 +1890,7 @@ void LayoutGrid::applyStretchAlignmentToTracksIfNeeded(GridTrackSizingDirection
 
 void LayoutGrid::layoutGridItems(GridSizingData& sizingData)
 {
+    sizingData.sizingOperation = TrackSizing;

[jfernandez, 2016/09/14 21:54:46]

Why we need to do this ?  Wouldn't be better place in the layoutBlock function ?
Or perhaps after finishing the computeIntrinsicLogicalHeight logic. 

[svillar, 2016/09/15 10:04:34]

We need this because the layout of the items involves calling some functions
whose behavior depend on that.

We didn't need that before because we always had a call to
computeUsedBreadthOfGridTracks(), something that does not happen now.

We can do it indeed inside computeIntrinsicLogicalHeight() as well. BTW I think
I'm renaming that function because it is a bit confusing. Perhaps
computeRowSizesForIndefiniteHeight() or something more explicit.

     populateGridPositionsForDirection(sizingData, ForColumns);
     populateGridPositionsForDirection(sizingData, ForRows);
     m_gridItemsOverflowingGridArea.resize(0);