[LayoutNG] Compute baseline from fragment tree

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

Index: third_party/WebKit/Source/core/layout/LayoutBlock.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index 403034d33a600615a5bb2b6ac676e12bcf7f600a..68b55f5c4543d58dc23872407c9f683329de62e5 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -1723,11 +1723,23 @@ int LayoutBlock::FirstLineBoxBaseline() const {
   return -1;
 }
 
+bool LayoutBlock::UseLogicalBottomMarginEdgeForInlineBlockBaseline() 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
+  // either no in-flow line boxes or if its 'overflow' property has a computed
+  // value other than 'visible', in which case the baseline is the bottom
+  // margin edge.
+  // We likewise avoid using the last line box in the case of size containment,
+  // where the block's contents shouldn't be considered when laying out its
+  // ancestors or siblings.
+  return (!Style()->IsOverflowVisible() &&
+          !ShouldIgnoreOverflowPropertyForInlineBlockBaseline()) ||
+         Style()->ContainsSize();
+}
+
 int LayoutBlock::InlineBlockBaseline(LineDirectionMode line_direction) const {
   DCHECK(!ChildrenInline());
-  if ((!Style()->IsOverflowVisible() &&
-       !ShouldIgnoreOverflowPropertyForInlineBlockBaseline()) ||
-      Style()->ContainsSize()) {
+  if (UseLogicalBottomMarginEdgeForInlineBlockBaseline()) {
     // We are not calling LayoutBox::baselinePosition here because the caller
     // should add the margin-top/margin-right, not us.
     return (line_direction == kHorizontalLine ? Size().Height() + MarginBottom()