[TableNG] Simplify table interface

CellPreceding and CellAbove were only used to determine if
this was the first cell in the table.

Bug: 958381
Change-Id: I372331b7a9534200ae7f060a5b67d91d9bd7ec49
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1896036
Auto-Submit: Aleks Totic <atotic@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Aleks Totic <atotic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711921}

third_party/blink/renderer/core/editing/iterators/text_iterator.cc

@@ -579,7 +579,7 @@ bool TextIteratorAlgorithm<Strategy>::ShouldEmitTabBeforeNode(
   const LayoutNGTableCellInterface* rc =
       ToInterface<LayoutNGTableCellInterface>(r);
   const LayoutNGTableInterface* t = rc->TableInterface();
-  return t && (t->CellInterfacePreceding(*rc) || t->CellInterfaceAbove(*rc));
+  return t && !t->IsFirstCell(*rc);
 }
 
 template <typename Strategy>

third_party/blink/renderer/core/layout/layout_table.cc

@@ -1871,14 +1871,9 @@ bool LayoutTable::PaintedOutputOfObjectHasNoEffectRegardlessOfSize() const {
 }
 
 // LayoutNGTableCellInterface API
-LayoutNGTableCellInterface* LayoutTable::CellInterfacePreceding(
-    const LayoutNGTableCellInterface& cell) const {
-  return CellPreceding(*cell.ToLayoutTableCell());
-}
-
-LayoutNGTableCellInterface* LayoutTable::CellInterfaceAbove(
-    const LayoutNGTableCellInterface& cell) const {
-  return CellAbove(*cell.ToLayoutTableCell());
+bool LayoutTable::IsFirstCell(const LayoutNGTableCellInterface& cell) const {
+  const LayoutTableCell& layout_cell = *cell.ToLayoutTableCell();
+  return !(CellPreceding(layout_cell) || CellAbove(layout_cell));
 }
 
 }  // namespace blink

third_party/blink/renderer/core/layout/layout_table.h

@@ -448,10 +448,7 @@ class CORE_EXPORT LayoutTable final : public LayoutBlock,
   LayoutNGTableSectionInterface* SectionBelowInterface(
       const LayoutNGTableSectionInterface*,
       SkipEmptySectionsValue) const final;
-  LayoutNGTableCellInterface* CellInterfacePreceding(
-      const LayoutNGTableCellInterface& cell) const final;
-  LayoutNGTableCellInterface* CellInterfaceAbove(
-      const LayoutNGTableCellInterface& cell) const final;
+  bool IsFirstCell(const LayoutNGTableCellInterface&) const final;
 
   // LayoutNGTableInterface methods end.
 

third_party/blink/renderer/core/layout/ng/table/layout_ng_table_interface.h

@@ -44,10 +44,7 @@ class LayoutNGTableInterface {
   virtual LayoutNGTableSectionInterface* SectionBelowInterface(
       const LayoutNGTableSectionInterface*,
       SkipEmptySectionsValue) const = 0;
-  virtual LayoutNGTableCellInterface* CellInterfacePreceding(
-      const LayoutNGTableCellInterface&) const = 0;
-  virtual LayoutNGTableCellInterface* CellInterfaceAbove(
-      const LayoutNGTableCellInterface&) const = 0;
+  virtual bool IsFirstCell(const LayoutNGTableCellInterface&) const = 0;
 };
 
 template <>