[FragmentItem] Make items const

This patch adds `const` to the instances of |NGFragmentItem|.

Bug: 982194
Change-Id: Id8262130e0e516c904c4f441fb05b04076d866d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2139635Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758201}

third_party/blink/renderer/core/layout/ng/inline/ng_fragment_items.cc

@@ -23,7 +23,7 @@ NGFragmentItems::NGFragmentItems(NGFragmentItemsBuilder* builder)
       first_line_text_content_(std::move(builder->first_line_text_content_)) {}
 
 void NGFragmentItems::AssociateWithLayoutObject() const {
-  const Vector<scoped_refptr<NGFragmentItem>>* items = &items_;
+  const Vector<scoped_refptr<const NGFragmentItem>>* items = &items_;
   DCHECK(std::all_of(items->begin(), items->end(), [](const auto& item) {
     return !item->DeltaToNextForSameLayoutObject();
   }));
@@ -62,8 +62,7 @@ void NGFragmentItems::ClearAssociatedFragments() const {
   if (items_.size() <= 1)
     return;
   LayoutObject* last_object = nullptr;
-  for (const auto& item : base::span<const scoped_refptr<NGFragmentItem>>(
-           items_.begin() + 1, items_.end())) {
+  for (const auto& item : base::make_span(items_.begin() + 1, items_.end())) {
     if (!ShouldAssociateWithLayoutObject(*item)) {
       // These items are not associated and that no need to clear.
       DCHECK_EQ(item->DeltaToNextForSameLayoutObject(), 0u);

third_party/blink/renderer/core/layout/ng/inline/ng_fragment_items.h

@@ -20,7 +20,9 @@ class CORE_EXPORT NGFragmentItems {
  public:
   NGFragmentItems(NGFragmentItemsBuilder* builder);
 
-  const Vector<scoped_refptr<NGFragmentItem>>& Items() const { return items_; }
+  const Vector<scoped_refptr<const NGFragmentItem>>& Items() const {
+    return items_;
+  }
 
   const String& Text(bool first_line) const {
     return UNLIKELY(first_line) ? first_line_text_content_ : text_content_;
@@ -36,7 +38,7 @@ class CORE_EXPORT NGFragmentItems {
 
  private:
   // TODO(kojii): inline capacity TBD.
-  Vector<scoped_refptr<NGFragmentItem>> items_;
+  Vector<scoped_refptr<const NGFragmentItem>> items_;
   String text_content_;
   String first_line_text_content_;
 };

third_party/blink/renderer/core/layout/ng/inline/ng_fragment_items_builder.cc

@@ -191,10 +191,10 @@ void NGFragmentItemsBuilder::AddItems(const NGFragmentItems& items,
   first_line_text_content_ = items.Text(true);
 }
 
-const Vector<scoped_refptr<NGFragmentItem>>& NGFragmentItemsBuilder::Items(
-    WritingMode writing_mode,
-    TextDirection direction,
-    const PhysicalSize& outer_size) {
+const Vector<scoped_refptr<const NGFragmentItem>>&
+NGFragmentItemsBuilder::Items(WritingMode writing_mode,
+                              TextDirection direction,
+                              const PhysicalSize& outer_size) {
   ConvertToPhysical(writing_mode, direction, outer_size);
   return items_;
 }
@@ -212,13 +212,13 @@ void NGFragmentItemsBuilder::ConvertToPhysical(WritingMode writing_mode,
   // convert their logical offsets.
   const WritingMode line_writing_mode = ToLineWritingMode(writing_mode);
 
-  scoped_refptr<NGFragmentItem>* item_iter = items_.begin();
+  scoped_refptr<const NGFragmentItem>* item_iter = items_.begin();
   const LogicalOffset* offset = offsets_.begin();
   for (; item_iter != items_.end(); ++item_iter, ++offset) {
     DCHECK_NE(offset, offsets_.end());
-    NGFragmentItem* item = item_iter->get();
-    item->SetOffset(offset->ConvertToPhysical(writing_mode, direction,
-                                              outer_size, item->Size()));
+    const NGFragmentItem* item = item_iter->get();
+    const_cast<NGFragmentItem*>(item)->SetOffset(offset->ConvertToPhysical(
+        writing_mode, direction, outer_size, item->Size()));
 
     // Transform children of lines separately from children of the block,
     // because they may have different directions from the block. To do
@@ -236,7 +236,7 @@ void NGFragmentItemsBuilder::ConvertToPhysical(WritingMode writing_mode,
           item = item_iter->get();
           // Use `kLtr` because inline items are after bidi-reoder, and that
           // their offset is visual, not logical.
-          item->SetOffset(
+          const_cast<NGFragmentItem*>(item)->SetOffset(
               offset->ConvertToPhysical(line_writing_mode, TextDirection::kLtr,
                                         line_box_bounds.size, item->Size()) +
               line_box_bounds.offset);
@@ -251,7 +251,7 @@ void NGFragmentItemsBuilder::ConvertToPhysical(WritingMode writing_mode,
 base::Optional<LogicalOffset> NGFragmentItemsBuilder::LogicalOffsetFor(
     const LayoutObject& layout_object) const {
   DCHECK_EQ(items_.size(), offsets_.size());
-  for (const scoped_refptr<NGFragmentItem>& item : items_) {
+  for (const scoped_refptr<const NGFragmentItem>& item : items_) {
     if (item->GetLayoutObject() == &layout_object)
       return offsets_[&item - items_.begin()];
   }

third_party/blink/renderer/core/layout/ng/inline/ng_fragment_items_builder.h

@@ -73,7 +73,7 @@ class CORE_EXPORT NGFragmentItemsBuilder {
   // containing block geometry for OOF-positioned nodes.
   //
   // Once this method has been called, new items cannot be added.
-  const Vector<scoped_refptr<NGFragmentItem>>&
+  const Vector<scoped_refptr<const NGFragmentItem>>&
   Items(WritingMode, TextDirection, const PhysicalSize& outer_size);
 
   // Build a |NGFragmentItems|. The builder cannot build twice because data set
@@ -90,7 +90,7 @@ class CORE_EXPORT NGFragmentItemsBuilder {
                          TextDirection direction,
                          const PhysicalSize& outer_size);
 
-  Vector<scoped_refptr<NGFragmentItem>> items_;
+  Vector<scoped_refptr<const NGFragmentItem>> items_;
   Vector<LogicalOffset> offsets_;
   String text_content_;
   String first_line_text_content_;

third_party/blink/renderer/core/layout/ng/inline/ng_inline_cursor.h

@@ -45,7 +45,7 @@ class CORE_EXPORT NGInlineCursorPosition {
   STACK_ALLOCATED();
 
  public:
-  using ItemsSpan = base::span<const scoped_refptr<NGFragmentItem>>;
+  using ItemsSpan = base::span<const scoped_refptr<const NGFragmentItem>>;
 
   const NGPaintFragment* PaintFragment() const { return paint_fragment_; }
   const NGFragmentItem* Item() const { return item_; }
@@ -170,7 +170,7 @@ class CORE_EXPORT NGInlineCursor {
   STACK_ALLOCATED();
 
  public:
-  using ItemsSpan = base::span<const scoped_refptr<NGFragmentItem>>;
+  using ItemsSpan = base::span<const scoped_refptr<const NGFragmentItem>>;
 
   explicit NGInlineCursor(const LayoutBlockFlow& block_flow);
   explicit NGInlineCursor(const NGFragmentItems& items);

third_party/blink/renderer/core/layout/ng/ng_box_fragment_builder.cc

@@ -78,7 +78,7 @@ void GatherInlineContainerFragmentsFromLinebox(
 }
 
 void GatherInlineContainerFragmentsFromItems(
-    const Vector<scoped_refptr<NGFragmentItem>>& items,
+    const Vector<scoped_refptr<const NGFragmentItem>>& items,
     const PhysicalOffset& box_offset,
     NGBoxFragmentBuilder::InlineContainingBlockMap* inline_containing_block_map,
     HashMap<const LayoutObject*, LineBoxPair>* containing_linebox_map) {