[LayoutNG] Add "use first line style" to NGConstraintSpace

This patch adds UseFirstLineStyle() to NGConstraintSpace, and
removes NGBaselineAlgorithmType::kAtomicInlineForFirstLine.

The distinction between kAtomicInline and kAtomicInlineForFirstLine
are not available in many cases, and these values are exclusive.
Having UseFirstLineStyle() in NGConstraintSpace is more reasonable.

Bug: 636993
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: I19e4124e82b86ba87318f6a08aa47e958dbf53ad
Reviewed-on: https://chromium-review.googlesource.com/688259
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505324}

third_party/WebKit/Source/core/layout/ng/inline/ng_baseline.h

@@ -16,8 +16,6 @@ class NGLayoutInputNode;
 enum class NGBaselineAlgorithmType {
   // Compute baselines for atomic inlines.
   kAtomicInline,
-  // Compute baselines for atomic inlines using the first line style.
-  kAtomicInlineForFirstLine,
   // Compute baseline of first line box.
   kFirstLine
 };

third_party/WebKit/Source/core/layout/ng/inline/ng_inline_layout_algorithm.cc

@@ -312,10 +312,7 @@ NGInlineBoxState* NGInlineLayoutAlgorithm::PlaceAtomicInline(
       ConstraintSpace().WritingMode(),
       ToNGPhysicalBoxFragment(*item_result->layout_result->PhysicalFragment()));
   NGLineHeightMetrics metrics = fragment.BaselineMetrics(
-      {line_info.UseFirstLineStyle()
-           ? NGBaselineAlgorithmType::kAtomicInlineForFirstLine
-           : NGBaselineAlgorithmType::kAtomicInline,
-       baseline_type_});
+      {NGBaselineAlgorithmType::kAtomicInline, baseline_type_});
   box->metrics.Unite(metrics);
 
   LayoutUnit line_top = item_result->margins.block_start - metrics.ascent;
@@ -499,7 +496,7 @@ void NGInlineLayoutAlgorithm::PropagateBaselinesFromChildren() {
   for (const auto& request : requests) {
     switch (request.algorithm_type) {
       case NGBaselineAlgorithmType::kAtomicInline:
-      case NGBaselineAlgorithmType::kAtomicInlineForFirstLine:
+        // Propagate from the last line box.
         for (unsigned i = container_builder_.Children().size(); i--;) {
           if (AddBaseline(request, container_builder_.Children()[i].get(),
                           container_builder_.Offsets()[i].block_offset))
@@ -507,6 +504,7 @@ void NGInlineLayoutAlgorithm::PropagateBaselinesFromChildren() {
         }
         break;
       case NGBaselineAlgorithmType::kFirstLine:
+        // Propagate from the first line box.
         for (unsigned i = 0; i < container_builder_.Children().size(); i++) {
           if (AddBaseline(request, container_builder_.Children()[i].get(),
                           container_builder_.Offsets()[i].block_offset))

third_party/WebKit/Source/core/layout/ng/inline/ng_line_breaker.cc

@@ -482,10 +482,9 @@ NGLineBreaker::LineBreakState NGLineBreaker::HandleAtomicInline(
   // Request to compute baseline during the layout, except when we know the box
   // would synthesize box-baseline.
   if (NGBaseline::ShouldPropagateBaselines(layout_box)) {
+    space_builder.SetUseFirstLineStyle(line_info.UseFirstLineStyle());
     space_builder.AddBaselineRequest(
-        {line_info.UseFirstLineStyle()
-             ? NGBaselineAlgorithmType::kAtomicInlineForFirstLine
-             : NGBaselineAlgorithmType::kAtomicInline,
+        {NGBaselineAlgorithmType::kAtomicInline,
          IsHorizontalWritingMode(constraint_space_.WritingMode())
              ? FontBaseline::kAlphabeticBaseline
              : FontBaseline::kIdeographicBaseline});

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

@@ -1209,7 +1209,6 @@ void NGBlockLayoutAlgorithm::PropagateBaselinesFromChildren() {
   for (const auto& request : requests) {
     switch (request.algorithm_type) {
       case NGBaselineAlgorithmType::kAtomicInline:
-      case NGBaselineAlgorithmType::kAtomicInlineForFirstLine:
         for (unsigned i = container_builder_.Children().size(); i--;) {
           if (AddBaseline(request, container_builder_.Children()[i].get(),
                           container_builder_.Offsets()[i].block_offset))

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

@@ -515,10 +515,8 @@ void NGBlockNode::CopyBaselinesFromOldLayout(
   for (const auto& request : requests) {
     switch (request.algorithm_type) {
       case NGBaselineAlgorithmType::kAtomicInline:
-        AddAtomicInlineBaselineFromOldLayout(request, false, builder);
-        break;
-      case NGBaselineAlgorithmType::kAtomicInlineForFirstLine:
-        AddAtomicInlineBaselineFromOldLayout(request, true, builder);
+        AddAtomicInlineBaselineFromOldLayout(
+            request, constraint_space.UseFirstLineStyle(), builder);
         break;
       case NGBaselineAlgorithmType::kFirstLine: {
         LayoutUnit position = box_->FirstLineBoxBaseline();

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

@@ -27,6 +27,7 @@ NGConstraintSpace::NGConstraintSpace(
     NGFragmentationType block_direction_fragmentation_type,
     bool is_new_fc,
     bool is_anonymous,
+    bool use_first_line_style,
     const NGMarginStrut& margin_strut,
     const NGBfcOffset& bfc_offset,
     const WTF::Optional<NGBfcOffset>& floats_bfc_offset,
@@ -51,6 +52,7 @@ NGConstraintSpace::NGConstraintSpace(
       block_direction_fragmentation_type_(block_direction_fragmentation_type),
       is_new_fc_(is_new_fc),
       is_anonymous_(is_anonymous),
+      use_first_line_style_(use_first_line_style),
       writing_mode_(writing_mode),
       direction_(static_cast<unsigned>(direction)),
       margin_strut_(margin_strut),

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

@@ -95,6 +95,13 @@ class CORE_EXPORT NGConstraintSpace final
   // any borders or padding.
   bool IsAnonymous() const { return is_anonymous_; }
 
+  // Whether to use the ':first-line' style or not.
+  // Note, this is not about the first line of the content to layout, but
+  // whether the constraint space itself is on the first line, such as when it's
+  // an inline block.
+  // Also note this is true only when the document has ':first-line' rules.
+  bool UseFirstLineStyle() const { return use_first_line_style_; }
+
   // Whether exceeding the AvailableSize() triggers the presence of a scrollbar
   // for the indicated direction.
   // If exceeded the current layout should be aborted and invoked again with a
@@ -201,6 +208,7 @@ class CORE_EXPORT NGConstraintSpace final
       NGFragmentationType block_direction_fragmentation_type,
       bool is_new_fc,
       bool is_anonymous,
+      bool use_first_line_style,
       const NGMarginStrut& margin_strut,
       const NGBfcOffset& bfc_offset,
       const WTF::Optional<NGBfcOffset>& floats_bfc_offset,
@@ -232,6 +240,7 @@ class CORE_EXPORT NGConstraintSpace final
   unsigned is_new_fc_ : 1;
 
   unsigned is_anonymous_ : 1;
+  unsigned use_first_line_style_ : 1;
 
   unsigned writing_mode_ : 3;
   unsigned direction_ : 1;

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

@@ -27,6 +27,7 @@ NGConstraintSpaceBuilder::NGConstraintSpaceBuilder(NGWritingMode writing_mode,
       fragmentation_type_(kFragmentNone),
       is_new_fc_(false),
       is_anonymous_(false),
+      use_first_line_sytle_(false),
       text_direction_(static_cast<unsigned>(TextDirection::kLtr)),
       exclusion_space_(nullptr) {}
 
@@ -130,6 +131,12 @@ NGConstraintSpaceBuilder& NGConstraintSpaceBuilder::SetIsAnonymous(
   return *this;
 }
 
+NGConstraintSpaceBuilder& NGConstraintSpaceBuilder::SetUseFirstLineStyle(
+    bool use_first_line_sytle) {
+  use_first_line_sytle_ = use_first_line_sytle;
+  return *this;
+}
+
 NGConstraintSpaceBuilder& NGConstraintSpaceBuilder::SetUnpositionedFloats(
     Vector<RefPtr<NGUnpositionedFloat>>& unpositioned_floats) {
   unpositioned_floats_ = unpositioned_floats;
@@ -229,9 +236,9 @@ RefPtr<NGConstraintSpace> NGConstraintSpaceBuilder::ToConstraintSpace(
         is_inline_direction_triggers_scrollbar_,
         is_block_direction_triggers_scrollbar_,
         static_cast<NGFragmentationType>(fragmentation_type_), is_new_fc_,
-        is_anonymous_, margin_strut, bfc_offset, floats_bfc_offset,
-        exclusion_space, unpositioned_floats_, clearance_offset,
-        baseline_requests_));
+        is_anonymous_, use_first_line_sytle_, margin_strut, bfc_offset,
+        floats_bfc_offset, exclusion_space, unpositioned_floats_,
+        clearance_offset, baseline_requests_));
   }
   return WTF::AdoptRef(new NGConstraintSpace(
       out_writing_mode, static_cast<TextDirection>(text_direction_),
@@ -242,9 +249,9 @@ RefPtr<NGConstraintSpace> NGConstraintSpaceBuilder::ToConstraintSpace(
       is_block_direction_triggers_scrollbar_,
       is_inline_direction_triggers_scrollbar_,
       static_cast<NGFragmentationType>(fragmentation_type_), is_new_fc_,
-      is_anonymous_, margin_strut, bfc_offset, floats_bfc_offset,
-      exclusion_space, unpositioned_floats_, clearance_offset,
-      baseline_requests_));
+      is_anonymous_, use_first_line_sytle_, margin_strut, bfc_offset,
+      floats_bfc_offset, exclusion_space, unpositioned_floats_,
+      clearance_offset, baseline_requests_));
 }
 
 }  // namespace blink

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

@@ -55,6 +55,7 @@ class CORE_EXPORT NGConstraintSpaceBuilder final {
   NGConstraintSpaceBuilder& SetFragmentationType(NGFragmentationType);
   NGConstraintSpaceBuilder& SetIsNewFormattingContext(bool is_new_fc);
   NGConstraintSpaceBuilder& SetIsAnonymous(bool is_anonymous);
+  NGConstraintSpaceBuilder& SetUseFirstLineStyle(bool use_first_line_sytle);
 
   NGConstraintSpaceBuilder& SetUnpositionedFloats(
       Vector<RefPtr<NGUnpositionedFloat>>& unpositioned_floats);
@@ -103,6 +104,7 @@ class CORE_EXPORT NGConstraintSpaceBuilder final {
   unsigned fragmentation_type_ : 2;
   unsigned is_new_fc_ : 1;
   unsigned is_anonymous_ : 1;
+  unsigned use_first_line_sytle_ : 1;
   unsigned text_direction_ : 1;
 
   NGMarginStrut margin_strut_;