[css-grid] Implementation of Baseline Self-Alignment

third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 2511 matching lines @@
   for (const RootInlineBox* box = firstRootBox(); box;
        box = box->nextRootBox()) {
     count++;
     if (box == stopRootInlineBox)
       break;
   }
   return count;
 }
 
 int LayoutBlockFlow::firstLineBoxBaseline() const {
-  if (isWritingModeRoot() && !isRubyRun())
+  // Orthogonal grid items can participante in baseline alignment along column
+  // axis.
+  if (isWritingModeRoot() && !isRubyRun() && !isGridItem())
     return -1;
   if (!childrenInline())
     return LayoutBlock::firstLineBoxBaseline();
   if (firstLineBox()) {
     const SimpleFontData* fontData = style(true)->font().primaryFont();
     DCHECK(fontData);
     if (!fontData)
       return -1;
-    return (firstLineBox()->logicalTop() +
+    // logicalTop() gives the distance to 'over-edge', 'top' for horizontal and
+    // 'right' for vertical-lr and vertical-rl. However, as it happens in
+    // inlineBlockBaseline we will flip lines to compute the baseline in case of
+    // vertical-lr mode, hence we want the distance to 'left' edge.
+    // We perform the same operatio in LayoutBlockFlow::inlineBlockBaseline.
+    return ((styleRef().isFlippedLinesWritingMode()
+                 ? logicalHeight() - firstLineBox()->logicalBottom()
+                 : firstLineBox()->logicalTop()) +
             fontData->getFontMetrics().ascent(firstRootBox()->baselineType()))
         .toInt();
   }
   return -1;
 }
 
 int LayoutBlockFlow::inlineBlockBaseline(
     LineDirectionMode lineDirection) const {
   // CSS2.1 states that the baseline of an 'inline-block' is:
   // the baseline of the last line box in the normal flow, unless it has
@@ skipping 2050 matching lines @@
   return LayoutBlock::invalidatePaintIfNeeded(paintInvalidationState);
 }
 
 void LayoutBlockFlow::invalidateDisplayItemClients(
     PaintInvalidationReason invalidationReason) const {
   BlockFlowPaintInvalidator(*this).invalidateDisplayItemClients(
       invalidationReason);
 }
 
 }  // namespace blink