[LayoutNG] Handle border and padding when sizing a block and when placing its children.

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

Index: third_party/WebKit/Source/core/layout/ng/ng_length_utils.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_length_utils.cc b/third_party/WebKit/Source/core/layout/ng/ng_length_utils.cc
index f01a9e9353c377e4ddb5b572c52ba2769d9ac944..93697ed744405fb978dc6e882394fc106a443f42 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_length_utils.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_length_utils.cc
@@ -78,7 +78,8 @@ LayoutUnit computeInlineSizeForFragment(
   extent = std::max(extent, min);
 
   if (style.boxSizing() == BoxSizingContentBox) {
-    // TODO(layout-ng): Compute border/padding size and add it
+    extent += computeBorderAndPaddingInlineStart(constraintSpace, style);
+    extent += computeBorderAndPaddingInlineEnd(constraintSpace, style);
   }
 
   return extent;
@@ -110,12 +111,53 @@ LayoutUnit computeBlockSizeForFragment(const NGConstraintSpace& constraintSpace,
   extent = std::max(extent, min);
 
   if (style.boxSizing() == BoxSizingContentBox) {
-    // TODO(layout-ng): Compute border/padding size and add it
+    extent += computeBorderAndPaddingBlockStart(constraintSpace, style);
+    extent += computeBorderAndPaddingBlockEnd(constraintSpace, style);
   }
 
   return extent;
 }
 
+LayoutUnit computeBorderAndPaddingBlockStart(
+    const NGConstraintSpace& constraintSpace,
+    const ComputedStyle& style) {
+  // Percentages on block-direction padding are resolved against the containing
+  // block *inline size* - hence the call to resolveInlineLength().
+  LayoutUnit padding =
+      resolveInlineLength(constraintSpace, style.paddingBefore(),
+                          LengthResolveType::MarginBorderPaddingSize);
+  return padding + LayoutUnit(style.borderBeforeWidth());
+}
+
+LayoutUnit computeBorderAndPaddingBlockEnd(
+    const NGConstraintSpace& constraintSpace,
+    const ComputedStyle& style) {
+  // Percentages on block-direction padding are resolved against the containing
+  // block *inline size* - hence the call to resolveInlineLength().
+  LayoutUnit padding =
+      resolveInlineLength(constraintSpace, style.paddingAfter(),
+                          LengthResolveType::MarginBorderPaddingSize);
+  return padding + LayoutUnit(style.borderAfterWidth());
+}
+
+LayoutUnit computeBorderAndPaddingInlineStart(
+    const NGConstraintSpace& constraintSpace,
+    const ComputedStyle& style) {
+  LayoutUnit padding =
+      resolveInlineLength(constraintSpace, style.paddingStart(),
+                          LengthResolveType::MarginBorderPaddingSize);
+  return padding + LayoutUnit(style.borderStartWidth());
+}
+
+LayoutUnit computeBorderAndPaddingInlineEnd(
+    const NGConstraintSpace& constraintSpace,
+    const ComputedStyle& style) {
+  LayoutUnit padding =
+      resolveInlineLength(constraintSpace, style.paddingEnd(),
+                          LengthResolveType::MarginBorderPaddingSize);
+  return padding + LayoutUnit(style.borderEndWidth());
+}
+
 NGBoxStrut computeMargins(const NGConstraintSpace& constraintSpace,
                           const ComputedStyle& style) {
   // Margins always get computed relative to the inline size: