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

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

Index: third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.cc b/third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.cc
index ae4722e5639624aede739e87e0b97c50998941fa..3607bcd5b5e342b6d8286ec16c162014ae9c01f4 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.cc
@@ -47,7 +47,7 @@ bool NGBlockLayoutAlgorithm::Layout(const NGConstraintSpace* constraint_space,
       constraint_space_for_children_ =
           new NGConstraintSpace(*constraint_space, NGLogicalOffset(),
                                 NGLogicalSize(inline_size, block_size));
-      content_size_ = LayoutUnit();
+      content_size_ = computeBorderAndPaddingBefore(*constraint_space, *style_);
 
       builder_ = new NGFragmentBuilder(NGPhysicalFragmentBase::FragmentBox);
       builder_->SetInlineSize(inline_size).SetBlockSize(block_size);
@@ -66,10 +66,16 @@ bool NGBlockLayoutAlgorithm::Layout(const NGConstraintSpace* constraint_space,
         LayoutUnit margin_block_start =
             CollapseMargins(child_margins, fragment->MarginStrut());
 
+        // TODO(layout-ng): This is probably something we shouldn't calculate
+        // over and over again for each child.
+        LayoutUnit content_start_edge =
+            computeBorderAndPaddingStart(*constraint_space, *style_);
+
         // TODO(layout-ng): Support auto margins
-        builder_->AddChild(fragment,
-                           NGLogicalOffset(child_margins.inline_start,
-                                           content_size_ + margin_block_start));
+        builder_->AddChild(
+            fragment,
+            NGLogicalOffset(content_start_edge + child_margins.inline_start,
+                            content_size_ + margin_block_start));
 
         content_size_ += fragment->BlockSize() + margin_block_start;
         max_inline_size_ =