Refactor RecalcInkOverflow to take |const NGInlineCursor&|

This patch refactors |NGFragmentItem::RecalcInkOverflow| to
take |const NGInlineCursor&| instead of |NGInlineCursor*|.
With this refactoring, it is callers' responsibility to
advance the cursor.

This is to prepare using this function for self-painting
|LayoutInline|.

This patch has no behavior changes.

Bug: 1128199
Change-Id: Iee1964255f5d1c31b4d3cf4e1bb73b6c4b50f327
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2426213Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810173}

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

@@ -507,19 +507,18 @@ PhysicalRect NGFragmentItem::RecalcInkOverflowForCursor(
   DCHECK(cursor);
   DCHECK(!cursor->Current() || cursor->IsAtFirst());
   PhysicalRect contents_ink_overflow;
-  while (*cursor) {
+  for (; *cursor; cursor->MoveToNextSkippingChildren()) {
     const NGFragmentItem* item = cursor->CurrentItem();
     DCHECK(item);
     if (UNLIKELY(item->IsLayoutObjectDestroyedOrMoved())) {
       // TODO(crbug.com/1099613): This should not happen, as long as it is
       // layout-clean. It looks like there are cases where the layout is dirty.
       NOTREACHED();
-      cursor->MoveToNextSkippingChildren();
       continue;
     }
 
     PhysicalRect child_rect;
-    item->GetMutableForPainting().RecalcInkOverflow(cursor, &child_rect);
+    item->GetMutableForPainting().RecalcInkOverflow(*cursor, &child_rect);
     if (item->HasSelfPaintingLayer())
       continue;
     if (!child_rect.IsEmpty()) {
@@ -531,21 +530,18 @@ PhysicalRect NGFragmentItem::RecalcInkOverflowForCursor(
 }
 
 void NGFragmentItem::RecalcInkOverflow(
-    NGInlineCursor* cursor,
+    const NGInlineCursor& cursor,
     PhysicalRect* self_and_contents_rect_out) {
-  DCHECK_EQ(this, cursor->CurrentItem());
+  DCHECK_EQ(this, cursor.CurrentItem());
 
   if (UNLIKELY(IsLayoutObjectDestroyedOrMoved())) {
     // TODO(crbug.com/1099613): This should not happen, as long as it is really
     // layout-clean. It looks like there are cases where the layout is dirty.
     NOTREACHED();
-    cursor->MoveToNextSkippingChildren();
     return;
   }
 
   if (IsText()) {
-    cursor->MoveToNext();
-
     // Re-computing text item is not necessary, because all changes that needs
     // to re-compute ink overflow invalidate layout.
     if (IsInkOverflowComputed()) {
@@ -553,7 +549,7 @@ void NGFragmentItem::RecalcInkOverflow(
       return;
     }
 
-    NGTextFragmentPaintInfo paint_info = TextPaintInfo(cursor->Items());
+    NGTextFragmentPaintInfo paint_info = TextPaintInfo(cursor.Items());
     if (paint_info.shape_result) {
       ink_overflow_type_ = ink_overflow_.SetTextInkOverflow(
           InkOverflowType(), paint_info, Style(), Size(),
@@ -571,15 +567,13 @@ void NGFragmentItem::RecalcInkOverflow(
   // overflow to be stored in |LayoutBox|.
   if (LayoutBox* owner_box = MutableInkOverflowOwnerBox()) {
     DCHECK(!HasChildren());
-    cursor->MoveToNextSkippingChildren();
     owner_box->RecalcNormalFlowChildVisualOverflowIfNeeded();
     *self_and_contents_rect_out = owner_box->PhysicalVisualOverflowRect();
     return;
   }
 
   // Re-compute descendants, then compute the contents ink overflow from them.
-  NGInlineCursor descendants_cursor = cursor->CursorForDescendants();
-  cursor->MoveToNextSkippingChildren();
+  NGInlineCursor descendants_cursor = cursor.CursorForDescendants();
   PhysicalRect contents_rect = RecalcInkOverflowForCursor(&descendants_cursor);
 
   // |contents_rect| is relative to the inline formatting context. Make it

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

@@ -247,7 +247,7 @@ class CORE_EXPORT NGFragmentItem {
     STACK_ALLOCATED();
 
    public:
-    void RecalcInkOverflow(NGInlineCursor* cursor,
+    void RecalcInkOverflow(const NGInlineCursor& cursor,
                            PhysicalRect* self_and_contents_rect_out) {
       return item_.RecalcInkOverflow(cursor, self_and_contents_rect_out);
     }
@@ -409,9 +409,8 @@ class CORE_EXPORT NGFragmentItem {
   const LayoutBox* InkOverflowOwnerBox() const;
   LayoutBox* MutableInkOverflowOwnerBox();
 
-  // Re-compute the ink overflow for this item. |cursor| should be at |this|,
-  // and is advanced to the next item on return.
-  void RecalcInkOverflow(NGInlineCursor* cursor,
+  // Re-compute the ink overflow for this item. |cursor| should be at |this|.
+  void RecalcInkOverflow(const NGInlineCursor& cursor,
                          PhysicalRect* self_and_contents_rect_out);
 
   const LayoutObject* layout_object_;