SetInnerNode() needs to decide when to set box fragment.

There's some special logic for handling inert (that's INERT, not INNER)
nodes.

Fixes the following tests when LayoutNGFullPositionForPoint is enabled:

  external/wpt/inert/inert-inlines.tentative.html
  fast/dom/inert/inert-inlines.html

Bug: 1150362
Change-Id: I8ce278168555b1f4b53b6a5abf121637f4bd58bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2554557
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830934}

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

@@ -147,8 +147,8 @@ void HitTestResult::SetNodeAndPosition(
     Node* node,
     scoped_refptr<const NGPhysicalBoxFragment> box_fragment,
     const PhysicalOffset& position) {
-  SetBoxFragment(std::move(box_fragment));
-  SetNodeAndPosition(node, position);
+  local_point_ = position;
+  SetInnerNodeAndBoxFragment(node, std::move(box_fragment));
 }
 
 void HitTestResult::OverrideNodeAndPosition(Node* node,
@@ -285,10 +285,17 @@ HTMLAreaElement* HitTestResult::ImageAreaForImage() const {
 }
 
 void HitTestResult::SetInnerNode(Node* n) {
+  SetInnerNodeAndBoxFragment(n, /* box_fragment */ nullptr);
+}
+
+void HitTestResult::SetInnerNodeAndBoxFragment(
+    Node* n,
+    scoped_refptr<const NGPhysicalBoxFragment> box_fragment) {
   if (!n) {
     inner_possibly_pseudo_node_ = nullptr;
     inner_node_ = nullptr;
     inner_element_ = nullptr;
+    DCHECK(!box_fragment);
     box_fragment_ = nullptr;
     return;
   }
@@ -309,7 +316,9 @@ void HitTestResult::SetInnerNode(Node* n) {
     }
   }
 
-  if (RuntimeEnabledFeatures::LayoutNGFullPositionForPointEnabled()) {
+  if (box_fragment) {
+    SetBoxFragment(std::move(box_fragment));
+  } else if (RuntimeEnabledFeatures::LayoutNGFullPositionForPointEnabled()) {
     if (const LayoutBox* layout_box = n->GetLayoutBox()) {
       // Fragmentation-aware code will set the correct box fragment on its own,
       // but sometimes we enter legacy layout code when hit-testing, e.g. for

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

@@ -149,6 +149,8 @@ class CORE_EXPORT HitTestResult {
   const HitTestRequest& GetHitTestRequest() const { return hit_test_request_; }
 
   void SetInnerNode(Node*);
+  void SetInnerNodeAndBoxFragment(Node*,
+                                  scoped_refptr<const NGPhysicalBoxFragment>);
   void SetInertNode(Node*);
   HTMLAreaElement* ImageAreaForImage() const;
   void SetURLElement(Element*);