[FragmentItem] Replace NGPaintFragment in HitTestCulledInline

This patch replaces |NGPaintFragment| with |NGInlineCursor|
in |LayoutInline::HitTestCulledInline|. The parent cursor
needed here is available up in the call stack, plumbing is
needed to pass it down.

This is in preparation to support culled inline box in
|NGFragmentItem|.

This patch has no behavior changes.

Bug: 982194
Change-Id: Ic06b4d0669ab47e01fbace9dd5071fa3806f9181
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2164365Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762696}

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

@@ -1101,12 +1101,11 @@ bool LayoutInline::NodeAtPoint(HitTestResult& result,
                               hit_test_action);
 }
 
-bool LayoutInline::HitTestCulledInline(
-    HitTestResult& result,
-    const HitTestLocation& hit_test_location,
-    const PhysicalOffset& accumulated_offset,
-    const NGPaintFragment* container_fragment) {
-  DCHECK(container_fragment || !AlwaysCreateLineBoxes());
+bool LayoutInline::HitTestCulledInline(HitTestResult& result,
+                                       const HitTestLocation& hit_test_location,
+                                       const PhysicalOffset& accumulated_offset,
+                                       const NGInlineCursor* parent_cursor) {
+  DCHECK(parent_cursor || !AlwaysCreateLineBoxes());
   if (!VisibleToHitTestRequest(result.GetHitTestRequest()))
     return false;
 
@@ -1124,13 +1123,9 @@ bool LayoutInline::HitTestCulledInline(
   // NG generates purely physical rectangles here, while legacy sets the block
   // offset on the rectangles relatively to the block-start. NG is doing the
   // right thing. Legacy is wrong.
-  if (container_fragment) {
+  if (parent_cursor) {
     DCHECK(ContainingNGBlockFlow());
-    DCHECK(container_fragment->IsDescendantOfNotSelf(
-        *ContainingNGBlockFlow()->PaintFragment()));
-    DCHECK(container_fragment->PhysicalFragment().IsInline() ||
-           container_fragment->PhysicalFragment().IsLineBox());
-    NGInlineCursor cursor(*container_fragment);
+    NGInlineCursor cursor(*parent_cursor);
     for (cursor.MoveTo(*this); cursor; cursor.MoveToNextForSameLayoutObject())
       yield(cursor.Current().RectInContainerBlock());
   } else {

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

@@ -34,7 +34,9 @@
 namespace blink {
 
 class LayoutBlockFlow;
+class NGInlineCursor;
 class NGPaintFragment;
+
 // LayoutInline is the LayoutObject associated with display: inline.
 // This is called an "inline box" in CSS 2.1.
 // http://www.w3.org/TR/CSS2/visuren.html#inline-boxes
@@ -235,7 +237,7 @@ class CORE_EXPORT LayoutInline : public LayoutBoxModelObject {
   bool HitTestCulledInline(HitTestResult&,
                            const HitTestLocation&,
                            const PhysicalOffset& accumulated_offset,
-                           const NGPaintFragment* parent_fragment = nullptr);
+                           const NGInlineCursor* parent_cursor = nullptr);
 
   PhysicalOffset FirstLineBoxTopLeft() const {
     return FirstLineBoxTopLeftInternal().value_or(PhysicalOffset());

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

@@ -151,8 +151,9 @@ TEST_F(LayoutInlineTest, RegionHitTest) {
   const auto* div = To<LayoutBlockFlow>(lots_of_boxes->Parent());
   for (const NGPaintFragment* line : div->PaintFragment()->Children()) {
     DCHECK(line->PhysicalFragment().IsLineBox());
-    bool hit_outcome = lots_of_boxes->HitTestCulledInline(hit_result, location,
-                                                          hit_offset, line);
+    NGInlineCursor line_cursor(*line);
+    bool hit_outcome = lots_of_boxes->HitTestCulledInline(
+        hit_result, location, hit_offset, &line_cursor);
     EXPECT_FALSE(hit_outcome);
   }
   // Make sure that the inline is hit

third_party/blink/renderer/core/paint/ng/ng_box_fragment_painter.cc

@@ -97,6 +97,7 @@ bool FragmentVisibleToHitTestRequest(const NGPhysicalFragment& fragment,
 // box fragments.
 // @param physical_offset Physical offset of |fragment| in the paint layer.
 bool HitTestCulledInlineAncestors(HitTestResult& result,
+                                  const NGInlineCursor& parent_cursor,
                                   const NGPaintFragment& fragment,
                                   const NGPaintFragment* previous_sibling,
                                   const HitTestLocation& hit_test_location,
@@ -137,7 +138,7 @@ bool HitTestCulledInlineAncestors(HitTestResult& result,
     if (culled_parent->IsLayoutInline() &&
         ToLayoutInline(culled_parent)
             ->HitTestCulledInline(result, hit_test_location,
-                                  fallback_accumulated_offset, &parent))
+                                  fallback_accumulated_offset, &parent_cursor))
       return true;
 
     current_layout_object = culled_parent;
@@ -2121,9 +2122,9 @@ bool NGBoxFragmentPainter::HitTestPaintFragmentChildren(
       // fragment.
       const NGPaintFragment* previous_sibling =
           cursor ? cursor.Current().PaintFragment() : nullptr;
-      if (HitTestCulledInlineAncestors(*hit_test.result, *child_paint_fragment,
-                                       previous_sibling, hit_test.location,
-                                       child_offset))
+      if (HitTestCulledInlineAncestors(*hit_test.result, children,
+                                       *child_paint_fragment, previous_sibling,
+                                       hit_test.location, child_offset))
         return true;
     }
   }