[heap] Remove unecessary unprotected_memory_chunks_registry_enabled_

This is an unecessary boolean, that makes reason about the code more
complicated.

Bug: v8:12054
Change-Id: I5bdf2069ead427f53ce774e825fe9656e668480e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3268284
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77765}

src/heap/heap-inl.h

@@ -826,7 +826,6 @@ CodePageCollectionMemoryModificationScope::
     : heap_(heap) {
   if (heap_->write_protect_code_memory() &&
       !heap_->code_space_memory_modification_scope_depth()) {
-    heap_->EnableUnprotectedMemoryChunksRegistry();
     heap_->IncrementCodePageCollectionMemoryModificationScopeDepth();
   }
 }
@@ -838,7 +837,6 @@ CodePageCollectionMemoryModificationScope::
     heap_->DecrementCodePageCollectionMemoryModificationScopeDepth();
     if (heap_->code_page_collection_memory_modification_scope_depth() == 0) {
       heap_->ProtectUnprotectedMemoryChunks();
-      heap_->DisableUnprotectedMemoryChunksRegistry();
     }
   }
 }

src/heap/heap.cc

@@ -2650,7 +2650,7 @@ void Heap::ComputeFastPromotionMode() {
 
 void Heap::UnprotectAndRegisterMemoryChunk(MemoryChunk* chunk,
                                            UnprotectMemoryOrigin origin) {
-  if (unprotected_memory_chunks_registry_enabled_) {
+  if (code_page_collection_memory_modification_scope_depth_ > 0) {
     base::Optional<base::MutexGuard> guard;
     if (origin != UnprotectMemoryOrigin::kMainThread) {
       guard.emplace(&unprotected_memory_chunks_mutex_);
@@ -2671,7 +2671,7 @@ void Heap::UnregisterUnprotectedMemoryChunk(MemoryChunk* chunk) {
 }
 
 void Heap::ProtectUnprotectedMemoryChunks() {
-  DCHECK(unprotected_memory_chunks_registry_enabled_);
+  DCHECK_EQ(code_page_collection_memory_modification_scope_depth_, 0);
   for (auto chunk = unprotected_memory_chunks_.begin();
        chunk != unprotected_memory_chunks_.end(); chunk++) {
     CHECK(memory_allocator()->IsMemoryChunkExecutable(*chunk));

src/heap/heap.h

@@ -668,18 +668,6 @@ class Heap {
   void UnregisterUnprotectedMemoryChunk(MemoryChunk* chunk);
   V8_EXPORT_PRIVATE void ProtectUnprotectedMemoryChunks();
 
-  void EnableUnprotectedMemoryChunksRegistry() {
-    unprotected_memory_chunks_registry_enabled_ = true;
-  }
-
-  void DisableUnprotectedMemoryChunksRegistry() {
-    unprotected_memory_chunks_registry_enabled_ = false;
-  }
-
-  bool unprotected_memory_chunks_registry_enabled() {
-    return unprotected_memory_chunks_registry_enabled_;
-  }
-
   void IncrementCodePageCollectionMemoryModificationScopeDepth() {
     code_page_collection_memory_modification_scope_depth_++;
   }
@@ -2476,7 +2464,6 @@ class Heap {
 
   base::Mutex unprotected_memory_chunks_mutex_;
   std::unordered_set<MemoryChunk*> unprotected_memory_chunks_;
-  bool unprotected_memory_chunks_registry_enabled_ = false;
 
 #ifdef V8_ENABLE_ALLOCATION_TIMEOUT
   // If the --gc-interval flag is set to a positive value, this