[css-grid] Computing free space on indefinite sized grids

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 26b4afd42c9f6a66f70e7a0e1a2aeccb0f5cc909..3d87b15370992692f181efdb4a73bb5b062511ff 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -535,13 +535,19 @@ void LayoutGrid::layoutBlock(bool relayoutChildren) {
       sizingData.nextState();
       sizingData.sizingOperation = TrackSizing;
     }
-    setLogicalHeight(computeTrackBasedLogicalHeight(sizingData) +
-                     borderAndPaddingLogicalHeight() +
-                     scrollbarLogicalHeight());
+    LayoutUnit trackBasedLogicalHeight =
+        computeTrackBasedLogicalHeight(sizingData) +
+        borderAndPaddingLogicalHeight() + scrollbarLogicalHeight();
+    setLogicalHeight(trackBasedLogicalHeight);
 
     LayoutUnit oldClientAfterEdge = clientLogicalBottom();
     updateLogicalHeight();
 
+    // Once grid's indefinite height is resolved, we can compute the
+    // available free space for Content Alignment.
+    if (!cachedHasDefiniteLogicalHeight())
+      sizingData.freeSpace(ForRows) = logicalHeight() - trackBasedLogicalHeight;
+
     // 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).
@@ -3227,7 +3233,10 @@ ContentAlignmentData LayoutGrid::computeContentPositionAndDistributionOffset(
   OverflowAlignment overflow =
       isRowAxis ? styleRef().justifyContentOverflowAlignment()
                 : styleRef().alignContentOverflowAlignment();
-  if (availableFreeSpace <= 0 && overflow == OverflowAlignmentSafe)
+  // TODO (lajava): Default value for overflow isn't exaclty as 'unsafe'.
+  // https://drafts.csswg.org/css-align/#overflow-values
+  if (availableFreeSpace == 0 ||
+      (availableFreeSpace < 0 && overflow == OverflowAlignmentSafe))
     return {LayoutUnit(), LayoutUnit()};
 
   switch (position) {