[cleanup] Heap: Initialize trivial members at declaraton site

Bug: v8:8015
Change-Id: Ic247b288294259dea1795c909874920e9f37a871
Reviewed-on: https://chromium-review.googlesource.com/1238575Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56133}

src/heap/heap.cc

@@ -129,108 +129,14 @@ class IdleScavengeObserver : public AllocationObserver {
 };
 
 Heap::Heap()
-    : external_memory_(0),
-      external_memory_limit_(kExternalAllocationSoftLimit),
-      external_memory_at_last_mark_compact_(0),
-      external_memory_concurrently_freed_(0),
-      isolate_(nullptr),
-      code_range_size_(0),
-      // semispace_size_ should be a power of 2 and old_generation_size_ should
-      // be a multiple of Page::kPageSize.
-      max_semi_space_size_(8 * (kPointerSize / 4) * MB),
-      initial_semispace_size_(kMinSemiSpaceSizeInKB * KB),
-      max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
-      initial_max_old_generation_size_(max_old_generation_size_),
+    : initial_max_old_generation_size_(max_old_generation_size_),
       initial_old_generation_size_(max_old_generation_size_ /
                                    kInitalOldGenerationLimitFactor),
-      old_generation_size_configured_(false),
-      // Variables set based on semispace_size_ and old_generation_size_ in
-      // ConfigureHeap.
-      // Will be 4 * reserved_semispace_size_ to ensure that young
-      // generation can be aligned to its size.
-      maximum_committed_(0),
-      backing_store_bytes_(0),
-      survived_since_last_expansion_(0),
-      survived_last_scavenge_(0),
-      always_allocate_scope_count_(0),
       memory_pressure_level_(MemoryPressureLevel::kNone),
-      contexts_disposed_(0),
-      number_of_disposed_maps_(0),
-      new_space_(nullptr),
-      old_space_(nullptr),
-      code_space_(nullptr),
-      map_space_(nullptr),
-      lo_space_(nullptr),
-      new_lo_space_(nullptr),
-      read_only_space_(nullptr),
-      write_protect_code_memory_(false),
-      code_space_memory_modification_scope_depth_(0),
-      gc_state_(NOT_IN_GC),
-      gc_post_processing_depth_(0),
-      allocations_count_(0),
-      raw_allocations_hash_(0),
-      stress_marking_observer_(nullptr),
-      stress_scavenge_observer_(nullptr),
-      allocation_step_in_progress_(false),
-      max_marking_limit_reached_(0.0),
-      ms_count_(0),
-      gc_count_(0),
-      consecutive_ineffective_mark_compacts_(0),
-      mmap_region_base_(0),
-      remembered_unmapped_pages_index_(0),
       old_generation_allocation_limit_(initial_old_generation_size_),
-      inline_allocation_disabled_(false),
-      tracer_(nullptr),
-      promoted_objects_size_(0),
-      promotion_ratio_(0),
-      semi_space_copied_object_size_(0),
-      previous_semi_space_copied_object_size_(0),
-      semi_space_copied_rate_(0),
-      nodes_died_in_new_space_(0),
-      nodes_copied_in_new_space_(0),
-      nodes_promoted_(0),
-      maximum_size_scavenges_(0),
-      last_idle_notification_time_(0.0),
-      last_gc_time_(0.0),
-      mark_compact_collector_(nullptr),
-      minor_mark_compact_collector_(nullptr),
-      array_buffer_collector_(nullptr),
-      memory_allocator_(nullptr),
-      store_buffer_(nullptr),
-      incremental_marking_(nullptr),
-      concurrent_marking_(nullptr),
-      gc_idle_time_handler_(nullptr),
-      memory_reducer_(nullptr),
-      live_object_stats_(nullptr),
-      dead_object_stats_(nullptr),
-      scavenge_job_(nullptr),
-      idle_scavenge_observer_(nullptr),
-      new_space_allocation_counter_(0),
-      old_generation_allocation_counter_at_last_gc_(0),
-      old_generation_size_at_last_gc_(0),
       global_pretenuring_feedback_(kInitialFeedbackCapacity),
-      is_marking_flag_(false),
-      ring_buffer_full_(false),
-      ring_buffer_end_(0),
-      configured_(false),
-      current_gc_flags_(Heap::kNoGCFlags),
       current_gc_callback_flags_(GCCallbackFlags::kNoGCCallbackFlags),
-      external_string_table_(this),
-      gc_callbacks_depth_(0),
-      deserialization_complete_(false),
-      strong_roots_list_(nullptr),
-      heap_iterator_depth_(0),
-      local_embedder_heap_tracer_(nullptr),
-      fast_promotion_mode_(false),
-      force_oom_(false),
-      delay_sweeper_tasks_for_testing_(false),
-      pending_layout_change_object_(nullptr),
-      unprotected_memory_chunks_registry_enabled_(false)
-#ifdef V8_ENABLE_ALLOCATION_TIMEOUT
-      ,
-      allocation_timeout_(0)
-#endif  // V8_ENABLE_ALLOCATION_TIMEOUT
-{
+      external_string_table_(this) {
   // Ensure old_generation_size_ is a multiple of kPageSize.
   DCHECK_EQ(0, max_old_generation_size_ & (Page::kPageSize - 1));