[heap] Move to two-level free-list

src/heap/mark-compact.h

Index: src/heap/mark-compact.h
diff --git a/src/heap/mark-compact.h b/src/heap/mark-compact.h
index 20ac9f6c935873f164e2e062716757215ed68b41..2445434b6a9486f21820f8946e8a524670443bc4 100644
--- a/src/heap/mark-compact.h
+++ b/src/heap/mark-compact.h
@@ -489,18 +489,19 @@ class MarkCompactCollector {
   // address range.
   void RemoveObjectSlots(Address start_slot, Address end_slot);
 
-  //
-  // Free lists filled by sweeper and consumed by corresponding spaces
-  // (including compaction spaces).
-  //
-  base::SmartPointer<FreeList>& free_list_old_space() {
-    return free_list_old_space_;
-  }
-  base::SmartPointer<FreeList>& free_list_code_space() {
-    return free_list_code_space_;
-  }
-  base::SmartPointer<FreeList>& free_list_map_space() {
-    return free_list_map_space_;
+  base::Mutex* swept_pages_mutex() { return &swept_pages_mutex_; }
+  List<Page*>* swept_pages(AllocationSpace id) {
+    switch (id) {
+      case OLD_SPACE:
+        return &swept_old_space_pages_;
+      case CODE_SPACE:
+        return &swept_code_space_pages_;
+      case MAP_SPACE:
+        return &swept_map_space_pages_;
+      default:
+        UNREACHABLE();
+    }
+    return nullptr;
   }
 
  private:
@@ -755,9 +756,10 @@ class MarkCompactCollector {
   List<Page*> evacuation_candidates_;
   List<NewSpacePage*> newspace_evacuation_candidates_;
 
-  base::SmartPointer<FreeList> free_list_old_space_;
-  base::SmartPointer<FreeList> free_list_code_space_;
-  base::SmartPointer<FreeList> free_list_map_space_;
+  base::Mutex swept_pages_mutex_;
+  List<Page*> swept_old_space_pages_;
+  List<Page*> swept_code_space_pages_;
+  List<Page*> swept_map_space_pages_;
 
   SweepingList sweeping_list_old_space_;
   SweepingList sweeping_list_code_space_;