[css-grid] Performance optimization on the baseline-self alignment 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 9b70c14246c0977c6e1645927061b89b3aec95f0..3706e215f898145afc3903a1d4c54315eb8b7e43 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -331,7 +331,7 @@ void LayoutGrid::UpdateBlockLayout(bool relayout_children) {
     // logic. Hence, items located at fixed or flexible tracks can't
     // resolve correctly their size at this stage, which may lead to
     // an incorrect computation of their shared context's baseline.
-    ComputeBaselineAlignmentContext();
+    // ComputeBaselineAlignmentContext();
 
     // 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
@@ -2133,10 +2133,12 @@ LayoutUnit LayoutGrid::ColumnAxisOffsetForChild(const LayoutBox& child) const {
   LayoutUnit start_position = start_of_row + MarginBeforeForChild(child);
   if (HasAutoMarginsInColumnAxis(child))
     return start_position;
+  if (IsBaselineAlignmentForChild(child, kGridColumnAxis))
+    start_position += ColumnAxisBaselineOffsetForChild(child);
   GridAxisPosition axis_position = ColumnAxisPositionForChild(child);
   switch (axis_position) {
     case kGridAxisStart:
-      return start_position + ColumnAxisBaselineOffsetForChild(child);
+      return start_position;
     case kGridAxisEnd:
     case kGridAxisCenter: {
       size_t child_end_line = rows_span.EndLine();
@@ -2175,10 +2177,12 @@ LayoutUnit LayoutGrid::RowAxisOffsetForChild(const LayoutBox& child) const {
   LayoutUnit start_position = start_of_column + MarginStartForChild(child);
   if (HasAutoMarginsInRowAxis(child))
     return start_position;
+  if (IsBaselineAlignmentForChild(child, kGridRowAxis))
+    start_position += RowAxisBaselineOffsetForChild(child);
   GridAxisPosition axis_position = RowAxisPositionForChild(child);
   switch (axis_position) {
     case kGridAxisStart:
-      return start_position + RowAxisBaselineOffsetForChild(child);
+      return start_position;
     case kGridAxisEnd:
     case kGridAxisCenter: {
       size_t child_end_line = columns_span.EndLine();