Make slot-assignment-recalc-forbidden scope on a per-document basis

We need to increment (and decrement) a counter on a per-document basis because call
stack can span across different documents.

BUG 776656, 845770

Change-Id: Ib9e89448217e7e335ba3c32c9775c9aa9c8f28cf
Reviewed-on: https://chromium-review.googlesource.com/1069959Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Hayato Ito <hayato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561014}

third_party/blink/renderer/core/dom/document.cc

@@ -676,6 +676,9 @@ Document::Document(const DocumentInit& initializer,
       engagement_level_(mojom::blink::EngagementLevel::NONE),
       secure_context_state_(SecureContextState::kUnknown),
       ukm_source_id_(ukm::UkmRecorder::GetNewSourceID()),
+#if DCHECK_IS_ON()
+      slot_assignment_recalc_forbidden_recursion_depth_(0),
+#endif
       needs_to_record_ukm_outlive_time_(false) {
   if (frame_) {
     DCHECK(frame_->GetPage());
@@ -2094,7 +2097,8 @@ void Document::UpdateStyleAndLayoutTree() {
     GetSlotAssignmentEngine().RecalcSlotAssignments();
   }
 #if DCHECK_IS_ON()
-  SlotAssignmentRecalcForbiddenScope forbid_slot_assignment_recalc;
+  NestingLevelIncrementer slot_assignment_recalc_forbidden_scope(
+      slot_assignment_recalc_forbidden_recursion_depth_);
 #endif
 
   if (!NeedsLayoutTreeUpdate()) {

third_party/blink/renderer/core/dom/document.h

@@ -1412,6 +1412,12 @@ class CORE_EXPORT Document : public ContainerNode,
 
   SlotAssignmentEngine& GetSlotAssignmentEngine();
 
+#if DCHECK_IS_ON()
+  bool IsSlotAssignmentRecalcForbidden() {
+    return slot_assignment_recalc_forbidden_recursion_depth_ > 0;
+  }
+#endif
+
  protected:
   Document(const DocumentInit&, DocumentClassFlags = kDefaultDocumentClass);
 
@@ -1809,6 +1815,10 @@ class CORE_EXPORT Document : public ContainerNode,
   std::unique_ptr<ukm::UkmRecorder> ukm_recorder_;
   int64_t ukm_source_id_;
 
+#if DCHECK_IS_ON()
+  unsigned slot_assignment_recalc_forbidden_recursion_depth_;
+#endif
+
   bool needs_to_record_ukm_outlive_time_;
 
   Member<Policy> policy_;

third_party/blink/renderer/core/dom/slot_assignment.cc

@@ -219,8 +219,7 @@ void SlotAssignment::RecalcAssignment() {
   if (!needs_assignment_recalc_)
     return;
 #if DCHECK_IS_ON()
-  DCHECK(
-      !SlotAssignmentRecalcForbiddenScope::IsSlotAssignmentRecalcForbidden());
+  DCHECK(!owner_->GetDocument().IsSlotAssignmentRecalcForbidden());
 #endif
   needs_assignment_recalc_ = false;
 
@@ -385,18 +384,4 @@ void SlotAssignment::Trace(blink::Visitor* visitor) {
   visitor->Trace(owner_);
 }
 
-#if DCHECK_IS_ON()
-unsigned SlotAssignmentRecalcForbiddenScope::g_main_thread_counter_ = 0;
-
-unsigned& SlotAssignmentRecalcForbiddenScope::GetMutableCounter() {
-  if (IsMainThread())
-    return g_main_thread_counter_;
-
-  DEFINE_THREAD_SAFE_STATIC_LOCAL(WTF::ThreadSpecific<unsigned>,
-                                  slot_assignment_recalc_forbidden_counter_,
-                                  ());
-  return *slot_assignment_recalc_forbidden_counter_;
-}
-#endif
-
 }  // namespace blink

third_party/blink/renderer/core/dom/slot_assignment.h

@@ -87,41 +87,6 @@ class SlotAssignment final : public GarbageCollected<SlotAssignment> {
   unsigned slot_count_ : 30;
 };
 
-#if DCHECK_IS_ON()
-class SlotAssignmentRecalcForbiddenScope final {
-  STACK_ALLOCATED();
-  DISALLOW_COPY_AND_ASSIGN(SlotAssignmentRecalcForbiddenScope);
-
- public:
-  SlotAssignmentRecalcForbiddenScope() { Enter(); }
-  ~SlotAssignmentRecalcForbiddenScope() { Exit(); }
-
-  static bool IsSlotAssignmentRecalcForbidden() {
-    return GetMutableCounter() > 0;
-  }
-
- private:
-  static void Enter() {
-    if (IsMainThread()) {
-      ++g_main_thread_counter_;
-    } else {
-      ++GetMutableCounter();
-    }
-  }
-  static void Exit() {
-    DCHECK(IsSlotAssignmentRecalcForbidden());
-    if (IsMainThread()) {
-      --g_main_thread_counter_;
-    } else {
-      --GetMutableCounter();
-    }
-  }
-
-  static unsigned& GetMutableCounter();
-  static unsigned g_main_thread_counter_;
-};
-#endif
-
 }  // namespace blink
 
 #endif  // HTMLSlotAssignment_h