[LayoutNG] Fix margins on html element.

Existing layout is bizarre. Margins for a child are calculated inside the
childs layout. This includes the auto margins calculation as far as we
can tell.

This just does the "simple" margin calculation (no auto etc) as auto margins
etc only occur within block layout, which we now control.

We may have to refine this to include more behaviour if we discover other
cases we don't cover.

Bug: 635619
Change-Id: I944ae3435074441f06e118c59f8d2ad317227b32
Reviewed-on: https://chromium-review.googlesource.com/580291
Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488451}

third_party/WebKit/LayoutTests/TestExpectations

@@ -290,10 +290,6 @@ crbug.com/635619 [ Mac ] virtual/layout_ng/fast/block/float/overhanging-tall-blo
 ### virtual/layout_ng Mac 1px glyph difference.
 crbug.com/635619 [ Mac ] virtual/layout_ng/fast/block/basic/015.html [ Failure ]
 
-### virtual/layout_ng/external/wpt/css/CSS2/abspos
-crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/abspos/abspos-containing-block-initial-001.xht [ Failure ]
-crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/abspos/abspos-containing-block-initial-009a.xht [ Failure ]
-
 ### virtual/layout_ng/external/wpt/css/CSS2/floats
 crbug.com/719620 virtual/layout_ng/external/wpt/css/CSS2/floats/floats-placement-vertical-001a.xht [ Failure ]
 crbug.com/719620 virtual/layout_ng/external/wpt/css/CSS2/floats/floats-placement-vertical-001b.xht [ Failure ]
@@ -400,9 +396,7 @@ crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/inline-repl
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/inline-replaced-width-015.xht [ Failure ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/root-box-001.xht [ Failure ]
 
-# Margin collapsing quirks
-# https://html.spec.whatwg.org/multipage/rendering.html#margin-collapsing-quirks
-crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/blocks-025.xht [ Failure ]
+# Missing refs, these are also skipped for existing layout.
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/inline-block-002.xht [ Skip ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/inline-block-003.xht [ Skip ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/normal-flow/inline-block-004.xht [ Skip ]
@@ -453,8 +447,6 @@ crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/absolute-re
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/abspos-007.xht [ Failure ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/abspos-011.xht [ Failure ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/abspos-012.xht [ Failure ]
-crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/abspos-019.xht [ Failure ]
-crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/abspos-020.xht [ Failure ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/abspos-containing-block-001.xht [ Failure ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/abspos-containing-block-002.xht [ Failure ]
 crbug.com/635619 virtual/layout_ng/external/wpt/css/CSS2/positioning/abspos-containing-block-007.xht [ Failure ]

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

@@ -8,6 +8,7 @@
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_fragment.h"
 #include "core/layout/ng/ng_layout_result.h"
+#include "core/layout/ng/ng_length_utils.h"
 
 namespace blink {
 
@@ -41,11 +42,30 @@ void LayoutNGBlockFlow::UpdateBlockLayout(bool relayout_children) {
     SetLogicalTop(computed_values.position_);
   }
 
+  // We need to update our margins as these are calculated once and stored in
+  // LayoutBox::margin_box_outsets_. Typically this happens within
+  // UpdateLogicalWidth and UpdateLogicalHeight.
+  //
+  // This primarily fixes cases where we are embedded inside another layout,
+  // for example LayoutView, LayoutFlexibleBox, etc.
+  UpdateMargins(*constraint_space);
+
   for (NGOutOfFlowPositionedDescendant descendant :
        result->OutOfFlowPositionedDescendants())
     descendant.node.UseOldOutOfFlowPositioning();
 }
 
+void LayoutNGBlockFlow::UpdateMargins(
+    const NGConstraintSpace& constraint_space) {
+  NGBoxStrut margins =
+      ComputeMargins(constraint_space, StyleRef(),
+                     constraint_space.WritingMode(), StyleRef().Direction());
+  SetMarginBefore(margins.block_start);
+  SetMarginAfter(margins.block_end);
+  SetMarginStart(margins.inline_start);
+  SetMarginEnd(margins.inline_end);
+}
+
 NGInlineNodeData& LayoutNGBlockFlow::GetNGInlineNodeData() const {
   DCHECK(ng_inline_node_data_);
   return *ng_inline_node_data_.get();

third_party/WebKit/Source/core/layout/ng/layout_ng_block_flow.h

@@ -32,6 +32,8 @@ class CORE_EXPORT LayoutNGBlockFlow final : public LayoutBlockFlow {
  private:
   bool IsOfType(LayoutObjectType) const override;
 
+  void UpdateMargins(const NGConstraintSpace&);
+
   std::unique_ptr<NGInlineNodeData> ng_inline_node_data_;
 };