[LayoutNG] Add BoxType to distinguish different box fragments

Bug: 591099
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: I2f6d01a6351b07d8bc93ad016858f49f549cf89c
Reviewed-on: https://chromium-review.googlesource.com/722383
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509687}

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

@@ -41,6 +41,23 @@ bool AppendFragmentOffsetAndSize(const NGPhysicalFragment* fragment,
   return has_content;
 }
 
+String StringForBoxType(NGPhysicalFragment::NGBoxType box_type) {
+  switch (box_type) {
+    case NGPhysicalFragment::NGBoxType::kNormalBox:
+      return String();
+    case NGPhysicalFragment::NGBoxType::kInlineBlock:
+      return "inline-block";
+    case NGPhysicalFragment::NGBoxType::kFloating:
+      return "floating";
+    case NGPhysicalFragment::NGBoxType::kOutOfFlowPositioned:
+      return "out-of-flow-positioned";
+    case NGPhysicalFragment::NGBoxType::kAnonymousBox:
+      return "anonymous";
+  }
+  NOTREACHED();
+  return String();
+}
+
 void AppendFragmentToString(const NGPhysicalFragment* fragment,
                             StringBuilder* builder,
                             NGPhysicalFragment::DumpFlags flags,
@@ -54,6 +71,12 @@ void AppendFragmentToString(const NGPhysicalFragment* fragment,
   if (fragment->IsBox()) {
     if (flags & NGPhysicalFragment::DumpType) {
       builder->Append("Box");
+      String box_type = StringForBoxType(fragment->BoxType());
+      if (!box_type.IsEmpty()) {
+        builder->Append(" (");
+        builder->Append(box_type);
+        builder->Append(")");
+      }
       has_content = true;
     }
     has_content =
@@ -170,6 +193,43 @@ Node* NGPhysicalFragment::GetNode() const {
   return layout_object_ ? layout_object_->GetNode() : nullptr;
 }
 
+// TODO(kojii): This series of Is*() functions rely on LayoutObject for now, but
+// should be set by fragment builder.
+bool NGPhysicalFragment::IsInlineBlock() const {
+  return layout_object_ && layout_object_->IsAtomicInlineLevel();
+}
+
+bool NGPhysicalFragment::IsFloating() const {
+  return layout_object_ && layout_object_->IsFloating();
+}
+
+bool NGPhysicalFragment::IsOutOfFlowPositioned() const {
+  return layout_object_ && layout_object_->IsOutOfFlowPositioned();
+}
+
+bool NGPhysicalFragment::IsAnonymousBox() const {
+  return !layout_object_ || layout_object_->Style() != style_.get();
+}
+
+bool NGPhysicalFragment::IsBlockLayoutRoot() const {
+  if (IsAnonymousBox())
+    return false;
+  return layout_object_->IsAtomicInlineLevel() ||
+         layout_object_->IsFloatingOrOutOfFlowPositioned();
+}
+
+NGPhysicalFragment::NGBoxType NGPhysicalFragment::BoxType() const {
+  if (IsInlineBlock())
+    return NGPhysicalFragment::NGBoxType::kInlineBlock;
+  if (IsFloating())
+    return NGPhysicalFragment::NGBoxType::kFloating;
+  if (IsOutOfFlowPositioned())
+    return NGPhysicalFragment::NGBoxType::kOutOfFlowPositioned;
+  if (IsAnonymousBox())
+    return NGPhysicalFragment::NGBoxType::kAnonymousBox;
+  return NGPhysicalFragment::NGBoxType::kNormalBox;
+}
+
 NGPixelSnappedPhysicalBoxStrut NGPhysicalFragment::BorderWidths() const {
   unsigned edges = BorderEdges();
   NGPhysicalBoxStrut box_strut(
@@ -232,9 +292,10 @@ RefPtr<NGPhysicalFragment> NGPhysicalFragment::CloneWithoutOffset() const {
 }
 
 String NGPhysicalFragment::ToString() const {
-  return String::Format("Type: '%d' Size: '%s' Offset: '%s' Placed: '%d'",
-                        Type(), Size().ToString().Ascii().data(),
-                        Offset().ToString().Ascii().data(), IsPlaced());
+  return String::Format(
+      "Type: '%d' Size: '%s' Offset: '%s' Placed: '%d', BoxType: '%s'", Type(),
+      Size().ToString().Ascii().data(), Offset().ToString().Ascii().data(),
+      IsPlaced(), StringForBoxType(BoxType()).Ascii().data());
 }
 
 String NGPhysicalFragment::DumpFragmentTree(DumpFlags flags) const {

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

@@ -47,6 +47,13 @@ class CORE_EXPORT NGPhysicalFragment
     // When adding new values, make sure the bit size of |type_| is large
     // enough to store.
   };
+  enum NGBoxType {
+    kNormalBox,
+    kInlineBlock,
+    kFloating,
+    kOutOfFlowPositioned,
+    kAnonymousBox
+  };
 
   ~NGPhysicalFragment();
 
@@ -59,6 +66,21 @@ class CORE_EXPORT NGPhysicalFragment
   bool IsText() const { return Type() == NGFragmentType::kFragmentText; }
   bool IsLineBox() const { return Type() == NGFragmentType::kFragmentLineBox; }
 
+  // Returns the box type of this fragment.
+  NGBoxType BoxType() const;
+  // An inline block is represented as a kFragmentBox.
+  // TODO(eae): This isn't true for replaces elements at the moment.
+  bool IsInlineBlock() const;
+  bool IsFloating() const;
+  bool IsOutOfFlowPositioned() const;
+  // A box fragment that do not exist in LayoutObject tree. Its LayoutObject is
+  // co-owned by other fragments.
+  bool IsAnonymousBox() const;
+  // A block sub-layout starts on this fragment. Inline blocks, floats, out of
+  // flow positioned objects are such examples. This may be false on NG/legacy
+  // boundary.
+  bool IsBlockLayoutRoot() const;
+
   // The accessors in this class shouldn't be used by layout code directly,
   // instead should be accessed by the NGFragmentBase classes. These accessors
   // exist for paint, hit-testing, etc.