Use |NGTextOffset| in |NGInlineItemResult|

This patch has no behavior changes.

Bug: 982194
Change-Id: Id4318d42c90bc4aee277c8ca167067664cabe6fa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2154629
Auto-Submit: Koji Ishii <kojii@chromium.org>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#776811}

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

@@ -10,20 +10,17 @@
 
 namespace blink {
 
-NGInlineItemResult::NGInlineItemResult()
-    : item(nullptr), item_index(0), start_offset(0), end_offset(0) {}
+NGInlineItemResult::NGInlineItemResult() : item(nullptr), item_index(0) {}
 
 NGInlineItemResult::NGInlineItemResult(const NGInlineItem* item,
                                        unsigned index,
-                                       unsigned start,
-                                       unsigned end,
+                                       const NGTextOffset& text_offset,
                                        bool break_anywhere_if_overflow,
                                        bool should_create_line_box,
                                        bool has_unpositioned_floats)
     : item(item),
       item_index(index),
-      start_offset(start),
-      end_offset(end),
+      text_offset(text_offset),
       break_anywhere_if_overflow(break_anywhere_if_overflow),
       should_create_line_box(should_create_line_box),
       has_unpositioned_floats(has_unpositioned_floats) {}
@@ -87,13 +84,13 @@ bool NGLineInfo::ComputeNeedsAccurateEndPosition() const {
 void NGInlineItemResult::CheckConsistency(bool allow_null_shape_result) const {
   DCHECK(item);
   if (item->Type() == NGInlineItem::kText) {
-    DCHECK_LT(start_offset, end_offset);
+    text_offset.AssertNotEmpty();
     if (allow_null_shape_result && !shape_result)
       return;
     DCHECK(shape_result);
-    DCHECK_EQ(end_offset - start_offset, shape_result->NumCharacters());
-    DCHECK_EQ(start_offset, shape_result->StartIndex());
-    DCHECK_EQ(end_offset, shape_result->EndIndex());
+    DCHECK_EQ(Length(), shape_result->NumCharacters());
+    DCHECK_EQ(StartOffset(), shape_result->StartIndex());
+    DCHECK_EQ(EndOffset(), shape_result->EndIndex());
   }
 }
 #endif
@@ -107,7 +104,7 @@ unsigned NGLineInfo::InflowEndOffset() const {
     if (item.Type() == NGInlineItem::kText ||
         item.Type() == NGInlineItem::kControl ||
         item.Type() == NGInlineItem::kAtomicInline)
-      return item_result.end_offset;
+      return item_result.EndOffset();
   }
   return StartOffset();
 }
@@ -179,18 +176,18 @@ LayoutUnit NGLineInfo::ComputeTrailingSpaceWidth(
 
     // The last text item may contain trailing spaces if this is a last line,
     // has a forced break, or is 'white-space: pre'.
-    unsigned end_offset = item_result.end_offset;
+    unsigned end_offset = item_result.EndOffset();
     DCHECK(end_offset);
     if (item.Type() == NGInlineItem::kText) {
       const String& text = items_data_->text_content;
       if (end_offset && text[end_offset - 1] == kSpaceCharacter) {
         do {
           --end_offset;
-        } while (end_offset > item_result.start_offset &&
+        } while (end_offset > item_result.StartOffset() &&
                  text[end_offset - 1] == kSpaceCharacter);
 
         // If all characters in this item_result are spaces, check next item.
-        if (end_offset == item_result.start_offset) {
+        if (end_offset == item_result.StartOffset()) {
           trailing_spaces_width += item_result.inline_size;
           continue;
         }

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

@@ -32,11 +32,10 @@ struct CORE_EXPORT NGInlineItemResult {
   DISALLOW_NEW();
 
  public:
-  NGTextOffset TextOffset() const { return {start_offset, end_offset}; }
-  unsigned Length() const {
-    DCHECK_GT(end_offset, start_offset);
-    return end_offset - start_offset;
-  }
+  const NGTextOffset& TextOffset() const { return text_offset; }
+  unsigned StartOffset() const { return text_offset.start; }
+  unsigned EndOffset() const { return text_offset.end; }
+  unsigned Length() const { return text_offset.Length(); }
 
   LayoutUnit HyphenInlineSize() const {
     return hyphen_shape_result->SnappedWidth().ClampNegativeToZero();
@@ -52,8 +51,7 @@ struct CORE_EXPORT NGInlineItemResult {
   unsigned item_index;
 
   // The range of text content for this item.
-  unsigned start_offset;
-  unsigned end_offset;
+  NGTextOffset text_offset;
 
   // Inline size of this item.
   LayoutUnit inline_size;
@@ -133,8 +131,7 @@ struct CORE_EXPORT NGInlineItemResult {
   NGInlineItemResult();
   NGInlineItemResult(const NGInlineItem*,
                      unsigned index,
-                     unsigned start,
-                     unsigned end,
+                     const NGTextOffset& text_offset,
                      bool break_anywhere_if_overflow,
                      bool should_create_line_box,
                      bool has_unpositioned_floats);

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

@@ -854,10 +854,9 @@ base::Optional<LayoutUnit> NGInlineLayoutAlgorithm::ApplyJustify(
     if (item_result.shape_result) {
       scoped_refptr<ShapeResult> shape_result =
           item_result.shape_result->CreateShapeResult();
-      DCHECK_GE(item_result.start_offset, line_info->StartOffset());
-      DCHECK_EQ(shape_result->NumCharacters(),
-                item_result.end_offset - item_result.start_offset);
-      shape_result->ApplySpacing(spacing, item_result.start_offset -
+      DCHECK_GE(item_result.StartOffset(), line_info->StartOffset());
+      DCHECK_EQ(shape_result->NumCharacters(), item_result.Length());
+      shape_result->ApplySpacing(spacing, item_result.StartOffset() -
                                               line_info->StartOffset() -
                                               shape_result->StartIndex());
       item_result.inline_size = shape_result->SnappedWidth();
@@ -866,9 +865,9 @@ base::Optional<LayoutUnit> NGInlineLayoutAlgorithm::ApplyJustify(
       item_result.shape_result = ShapeResultView::Create(shape_result.get());
     } else if (item_result.item->Type() == NGInlineItem::kAtomicInline) {
       float offset = 0.f;
-      DCHECK_LE(line_info->StartOffset(), item_result.start_offset);
+      DCHECK_LE(line_info->StartOffset(), item_result.StartOffset());
       unsigned line_text_offset =
-          item_result.start_offset - line_info->StartOffset();
+          item_result.StartOffset() - line_info->StartOffset();
       DCHECK_EQ(kObjectReplacementCharacter, line_text[line_text_offset]);
       float space = spacing.ComputeSpacing(line_text_offset, offset);
       item_result.inline_size += space;

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

@@ -22,8 +22,7 @@ String ToString(NGInlineItemResults line, NGInlineNode node) {
   const String& text = node.ItemsData(false).text_content;
   for (const auto& item_result : line) {
     builder.Append(
-        StringView(text, item_result.start_offset,
-                   item_result.end_offset - item_result.start_offset));
+        StringView(text, item_result.StartOffset(), item_result.Length()));
   }
   return builder.ToString();
 }

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

@@ -23,6 +23,7 @@ struct CORE_EXPORT NGTextOffset {
   }
 
   void AssertValid() const { DCHECK_GE(end, start); }
+  void AssertNotEmpty() const { DCHECK_GT(end, start); }
 
   unsigned start;
   unsigned end;