[css-grid] Clearing override sizes before running grid's layout logic.

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 ec13d1934a0da3df498bbfaa44792491e7bfb277..de7fb5176c2c6efb5eaee2a622fc2272f1e7bd63 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -430,7 +430,7 @@ void LayoutGrid::repeatTracksSizingIfNeeded(GridSizingData& sizingData, LayoutUn
     // a new cycle of the sizing algorithm; there may be more. In addition, not all the
     // cases with orthogonal flows require this extra cycle; we need a more specific
     // condition to detect whether child's min-content contribution has changed or not.
-    if (m_hasAnyOrthogonalChild) {
+    if (!m_orthogonalChildren.isEmpty()) {
         computeTrackSizesForDefiniteSize(ForColumns, sizingData, availableSpaceForColumns);
         computeTrackSizesForDefiniteSize(ForRows, sizingData, availableSpaceForRows);
     }
@@ -452,6 +452,18 @@ void LayoutGrid::layoutBlock(bool relayoutChildren)
 
         LayoutSize previousSize = size();
 
+        // We need to clear both own and containingBlock override sizes to ensure we get the same
+        // result when grid's intrinsic size it's computed again.

[cbiesinger, 2016/09/27 09:47:42]

Please add "in the updateLogicalWidth call below" to the end of this comment

(also typo: it's -> is)

+        if (sizesLogicalWidthToFitContent(styleRef().logicalWidth()) || styleRef().logicalWidth().isIntrinsicOrAuto()) {
+            for (auto* child : m_orthogonalChildren) {

[cbiesinger, 2016/09/27 09:47:42]

This is a little subtle because m_orthogonalChildren gets initialized by
placeItemsOnGrid which is only called below. But this is correct anyway because
we only need to call this on children that previously did go through the grid
algorithm (and also, when we compute our intrinsic size we also call
placeItemsOnGrid). Could you add a comment explaining this?

+                if (child->isOutOfFlowPositioned())
+                    continue;
+                child->clearOverrideSize();
+                child->clearContainingBlockOverrideSize();
+                child->forceLayout();
+            }
+        }
+
         updateLogicalWidth();
         m_hasDefiniteLogicalHeight = hasDefiniteLogicalHeight();
 
@@ -1568,12 +1580,13 @@ void LayoutGrid::placeItemsOnGrid(SizingOperation sizingOperation)
 
     Vector<LayoutBox*> autoMajorAxisAutoGridItems;
     Vector<LayoutBox*> specifiedMajorAxisAutoGridItems;
-    m_hasAnyOrthogonalChild = false;
+    m_orthogonalChildren.shrink(0);
     for (LayoutBox* child = m_orderIterator.first(); child; child = m_orderIterator.next()) {
         if (child->isOutOfFlowPositioned())
             continue;
 
-        m_hasAnyOrthogonalChild = m_hasAnyOrthogonalChild || isOrthogonalChild(*child);
+        if (isOrthogonalChild(*child))
+            m_orthogonalChildren.append(child);
 
         GridArea area = cachedGridArea(*child);
         if (!area.rows.isIndefinite())