[heap] Cleanup MemoryChunk's declarations

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index eeb9d7a095004dae0ac9b548d168e427c77b8386..65e126ab9b3bfa004144e7e4d3e3bc3d9230b51a 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -3858,7 +3858,7 @@ int MarkCompactCollector::SweepInParallel(PagedSpace* space,
 
 int MarkCompactCollector::SweepInParallel(Page* page, PagedSpace* space) {
   int max_freed = 0;
-  if (page->TryLock()) {
+  if (page->mutex()->TryLock()) {
     // If this page was already swept in the meantime, we can return here.
     if (page->concurrent_sweeping_state().Value() != Page::kSweepingPending) {
       page->mutex()->Unlock();