[CSS Grid Layout] Update grid-auto-flow to the new syntax

Source/core/rendering/RenderGrid.cpp

Index: Source/core/rendering/RenderGrid.cpp
diff --git a/Source/core/rendering/RenderGrid.cpp b/Source/core/rendering/RenderGrid.cpp
index 80046d23d2c9225e15d8555bfc0590e01753b808..041c62a0e9cf12e0a2f6ed9ff40de6d66bd5ea28 100644
--- a/Source/core/rendering/RenderGrid.cpp
+++ b/Source/core/rendering/RenderGrid.cpp
@@ -211,7 +211,8 @@ void RenderGrid::addChild(RenderObject* newChild, RenderObject* beforeChild)
         return;
     }
 
-    if (style()->gridAutoFlow() != AutoFlowNone) {
+    // FIXME: Implement properly "stack" value in auto-placement algorithm.
+    if (style()->gridAutoFlow() != AutoFlowStackColumn && style()->gridAutoFlow() != AutoFlowStackRow) {
         // The grid needs to be recomputed as it might contain auto-placed items that will change their position.
         dirtyGrid();
         return;
@@ -260,7 +261,8 @@ void RenderGrid::removeChild(RenderObject* child)
 
     ASSERT(child->isBox());
 
-    if (style()->gridAutoFlow() != AutoFlowNone) {
+    // FIXME: Implement properly "stack" value in auto-placement algorithm.
+    if (style()->gridAutoFlow() != AutoFlowStackColumn && style()->gridAutoFlow() != AutoFlowStackRow) {
         // The grid needs to be recomputed as it might contain auto-placed items that will change their position.
         dirtyGrid();
         return;
@@ -810,7 +812,8 @@ void RenderGrid::placeItemsOnGrid()
     ASSERT(gridRowCount() >= style()->gridTemplateRows().size());
     ASSERT(gridColumnCount() >= style()->gridTemplateColumns().size());
 
-    if (autoFlow == AutoFlowNone) {
+    // FIXME: Implement properly "stack" value in auto-placement algorithm.
+    if (autoFlow == AutoFlowStackColumn || autoFlow == AutoFlowStackRow) {
         // If we did collect some grid items, they won't be placed thus never laid out.
         ASSERT(!autoMajorAxisAutoGridItems.size());
         ASSERT(!specifiedMajorAxisAutoGridItems.size());
@@ -933,15 +936,13 @@ void RenderGrid::placeAutoMajorAxisItemOnGrid(RenderBox* gridItem)
 GridTrackSizingDirection RenderGrid::autoPlacementMajorAxisDirection() const
 {
     GridAutoFlow flow = style()->gridAutoFlow();
-    ASSERT(flow != AutoFlowNone);
-    return (flow == AutoFlowColumn) ? ForColumns : ForRows;
+    return (flow == AutoFlowColumn || flow == AutoFlowColumnDense || flow == AutoFlowStackColumn) ? ForColumns : ForRows;
 }
 
 GridTrackSizingDirection RenderGrid::autoPlacementMinorAxisDirection() const
 {
     GridAutoFlow flow = style()->gridAutoFlow();
-    ASSERT(flow != AutoFlowNone);
-    return (flow == AutoFlowColumn) ? ForRows : ForColumns;
+    return (flow == AutoFlowColumn || flow == AutoFlowColumnDense || flow == AutoFlowStackColumn) ? ForRows : ForColumns;
 }
 
 void RenderGrid::dirtyGrid()