[css-grid] Fix grid-template-columns|rows computed style with content alignment

third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp

Index: third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
diff --git a/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp b/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
index 4b9e74e5be2fa2d3b5f5857f549740976cb546cf..e4083c36ea9b12d815c37ec2f3bccd9b77f143ff 100644
--- a/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
+++ b/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
@@ -644,18 +644,20 @@ static CSSValue* valueForGridTrackList(GridTrackSizingDirection direction, const
     CSSValueList* list = CSSValueList::createSpaceSeparated();
     size_t insertionIndex;
     if (isLayoutGrid) {
-        const Vector<LayoutUnit>& trackPositions = direction == ForColumns ? toLayoutGrid(layoutObject)->columnPositions() : toLayoutGrid(layoutObject)->rowPositions();
+        const auto* grid = toLayoutGrid(layoutObject);
+        const Vector<LayoutUnit>& trackPositions = direction == ForColumns ? grid->columnPositions() : grid->rowPositions();
         // There are at least #tracks + 1 grid lines (trackPositions). Apart from that, the grid container can generate implicit grid tracks,
         // so we'll have more trackPositions than trackSizes as the latter only contain the explicit grid.
         ASSERT(trackPositions.size() - 1 >= trackSizes.size());
 
         size_t i;
-        LayoutUnit gutterSize = toLayoutGrid(layoutObject)->guttersSize(direction, 2);
+        LayoutUnit gutterSize = grid->guttersSize(direction, 2);
+        LayoutUnit offsetBetweenTracks = grid->offsetBetweenTracks(direction);
         for (i = 0; i < trackPositions.size() - 2; ++i) {
             addValuesForNamedGridLinesAtIndex(orderedNamedGridLines, i, *list);
-            list->append(zoomAdjustedPixelValue(trackPositions[i + 1] - trackPositions[i] - gutterSize, style));
+            list->append(zoomAdjustedPixelValue(trackPositions[i + 1] - trackPositions[i] - gutterSize - offsetBetweenTracks, style));
         }
-        // Last track line does not have any gutter.
+        // Last track line does not have any gutter or distribution offset.
         addValuesForNamedGridLinesAtIndex(orderedNamedGridLines, i, *list);
         list->append(zoomAdjustedPixelValue(trackPositions[i + 1] - trackPositions[i], style));
         insertionIndex = trackPositions.size() - 1;