[heap] Simplify FreeList clearing friends.

Bug: v8:9093
Change-Id: I3e4187f8d47a8a6cf80cc2fa2d2b96d89628af35
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1585738
Auto-Submit: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61042}

src/heap/mark-compact.cc

@@ -3769,7 +3769,7 @@ void MarkCompactCollector::ReleaseEvacuationCandidates() {
 }
 
 void MarkCompactCollector::StartSweepSpace(PagedSpace* space) {
-  space->ClearStats();
+  space->ClearAllocatorState();
 
   int will_be_swept = 0;
   bool unused_page_present = false;

src/heap/spaces.cc

@@ -2941,7 +2941,7 @@ void FreeList::Reset() {
   for (int i = kFirstCategory; i < kNumberOfCategories; i++) {
     categories_[i] = nullptr;
   }
-  ResetStats();
+  wasted_bytes_ = 0;
 }
 
 size_t FreeList::Free(Address start, size_t size_in_bytes, FreeMode mode) {

src/heap/spaces.h

@@ -164,8 +164,6 @@ class FreeListCategory {
 
   void Reset();
 
-  void ResetStats() { Reset(); }
-
   void RepairFreeList(Heap* heap);
 
   // Relinks the category into the currently owning free list. Requires that the
@@ -1864,12 +1862,6 @@ class FreeList {
   // Clear the free list.
   void Reset();
 
-  void ResetStats() {
-    wasted_bytes_ = 0;
-    ForAllFreeListCategories(
-        [](FreeListCategory* category) { category->ResetStats(); });
-  }
-
   // Return the number of bytes available on the free list.
   size_t Available() {
     size_t available = 0;
@@ -2148,10 +2140,10 @@ class V8_EXPORT_PRIVATE PagedSpace
   // The stats are rebuilt during sweeping by adding each page to the
   // capacity and the size when it is encountered.  As free spaces are
   // discovered during the sweeping they are subtracted from the size and added
-  // to the available and wasted totals.
-  void ClearStats() {
+  // to the available and wasted totals. The free list is cleared as well.
+  void ClearAllocatorState() {
     accounting_stats_.ClearSize();
-    free_list_.ResetStats();
+    free_list_.Reset();
   }
 
   // Available bytes without growing.  These are the bytes on the free list.