[LayoutNG] Fix NeedsCollectInlines tp stop at atomic inlines

This patch stops propagation of setting NeedsCollectInlines
at atomic inlines.

Usually atomic inlines that have children are LayoutBlockFlow,
but LayoutSVGRoot is one example that are not LayoutBlockFlow.

This patch also clarifies the distinction when a parent of
object needs to collect from when the object itself needs to
collect.

Bug: 966699
Change-Id: I260824f3e8e211f842aa7990c6d504a3c72549b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1631016
Commit-Queue: Emil A Eklund <eae@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663760}

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

@@ -944,9 +944,24 @@ void LayoutObject::SetNeedsCollectInlines() {
   if (!RuntimeEnabledFeatures::LayoutNGEnabled())
     return;
 
+  if (NeedsCollectInlines())
+    return;
+
   if (UNLIKELY(IsSVGChild()))
     return;
 
+  // Don't mark |LayoutFlowThread| because |CollectInlines()| skips them.
+  if (!IsLayoutFlowThread())
+    SetNeedsCollectInlines(true);
+
+  if (LayoutObject* parent = Parent())
+    parent->SetChildNeedsCollectInlines();
+}
+
+void LayoutObject::SetChildNeedsCollectInlines() {
+  if (!RuntimeEnabledFeatures::LayoutNGEnabled())
+    return;
+
   LayoutObject* object = this;
   do {
     // Should not stop at |LayoutFlowThread| as |CollectInlines()| skips them.
@@ -957,7 +972,10 @@ void LayoutObject::SetNeedsCollectInlines() {
     if (object->NeedsCollectInlines())
       break;
     object->SetNeedsCollectInlines(true);
-    if (object->IsLayoutBlockFlow())
+    if (object->IsLayoutBlockFlow() ||
+        // Some LayoutReplaced have children (e.g., LayoutSVGRoot). Stop marking
+        // because their children belong to different context.
+        object->IsAtomicInlineLevel())
       break;
     object = object->Parent();
   } while (object);

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

@@ -1282,6 +1282,7 @@ class CORE_EXPORT LayoutObject : public ImageResourceObserver,
   // Mark this object needing to re-run |CollectInlines()|. Ancestors may be
   // marked too if needed.
   void SetNeedsCollectInlines();
+  void SetChildNeedsCollectInlines();
   void ClearNeedsCollectInlines() { SetNeedsCollectInlines(false); }
 
   void MarkContainerChainForLayout(bool schedule_relayout = true,

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

@@ -128,7 +128,7 @@ LayoutObject* LayoutObjectChildList::RemoveChildNode(
     }
 
     if (old_child->IsInLayoutNGInlineFormattingContext()) {
-      owner->SetNeedsCollectInlines();
+      owner->SetChildNeedsCollectInlines();
     }
   }
 
@@ -218,7 +218,7 @@ void LayoutObjectChildList::InsertChildNode(LayoutObject* owner,
 
     if (owner->IsInLayoutNGInlineFormattingContext() ||
         (owner->EverHadLayout() && owner->ChildrenInline())) {
-      owner->SetNeedsCollectInlines();
+      owner->SetChildNeedsCollectInlines();
     }
   }
 

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

@@ -21,6 +21,7 @@
 #include "third_party/blink/renderer/core/layout/ng/ng_physical_box_fragment.h"
 #include "third_party/blink/renderer/core/paint/ng/ng_paint_fragment.h"
 #include "third_party/blink/renderer/core/style/computed_style.h"
+#include "third_party/blink/renderer/core/svg_names.h"
 
 namespace blink {
 
@@ -1388,6 +1389,22 @@ TEST_F(NGInlineNodeTest, ClearFirstInlineFragmentOnSplitFlow) {
   EXPECT_EQ(line_box_fragment->FirstChild(), text_fragment_after_layout);
 }
 
+TEST_F(NGInlineNodeTest, AddChildToSVGRoot) {
+  SetBodyInnerHTML(R"HTML(
+    <div id="container">
+      text
+      <svg id="svg"></svg>
+    </div>
+  )HTML");
+
+  Element* svg = GetElementById("svg");
+  svg->appendChild(GetDocument().CreateRawElement(svg_names::kTextTag));
+  GetDocument().UpdateStyleAndLayoutTree();
+
+  LayoutObject* container = GetLayoutObjectByElementId("container");
+  EXPECT_FALSE(container->NeedsCollectInlines());
+}
+
 // https://crbug.com/911220
 TEST_F(NGInlineNodeTest, PreservedNewlineWithBidiAndRelayout) {
   SetupHtml("container",