Initial implementation of Collapsing Margins computational logic for LayoutNG

third_party/WebKit/Source/core/layout/ng/ng_units.cc

Index: third_party/WebKit/Source/core/layout/ng/ng_units.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_units.cc b/third_party/WebKit/Source/core/layout/ng/ng_units.cc
index 44f760022bc010bdfed88877ce118e97db567795..79918a4d661516a8830e0b2bee5388e44a108edd 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_units.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_units.cc
@@ -61,4 +61,29 @@ NGPhysicalOffset NGLogicalOffset::ConvertToPhysical(
   }
 }
 
+void NGMarginStrut::AppendMarginBlockStart(const LayoutUnit& value) {
+  if (value < 0) {
+    negative_margin_block_start =
+        -std::max(value.abs(), negative_margin_block_start.abs());
+  } else {
+    margin_block_start = std::max(value, margin_block_start);
+  }
+}
+
+void NGMarginStrut::AppendMarginBlockEnd(const LayoutUnit& value) {
+  if (value < 0) {
+    negative_margin_block_end =
+        -std::max(value.abs(), negative_margin_block_end.abs());
+  } else {
+    margin_block_end = std::max(value, margin_block_end);
+  }
+}
+
+String NGMarginStrut::ToString() const {
+  return String::format(
+      "Start: (%d %d) End: (%d %d)", negative_margin_block_start.toInt(),
+      margin_block_start.toInt(), negative_margin_block_end.toInt(),
+      margin_block_end.toInt());
+}
+
 }  // namespace blink