Oilpan: Remove unused lazy_sweep flag from NormalPage.

Change-Id: Ie81593dafa4e19f7d816b990fc81496d67634b9f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1660857Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669655}

third_party/blink/renderer/platform/heap/heap_page.cc

@@ -312,15 +312,6 @@ bool BaseArena::LazySweepWithDeadline(TimeTicks deadline) {
   DCHECK(GetThreadState()->SweepForbidden());
   DCHECK(ScriptForbiddenScope::IsScriptForbidden());
 
-  NormalPageArena* normal_arena = nullptr;
-  if (BasePage* top = unswept_pages_.Top()) {
-    if (!top->IsLargeObjectPage()) {
-      // Mark this NormalPageArena as being lazily swept.
-      NormalPage* normal_page = static_cast<NormalPage*>(top);
-      normal_arena = normal_page->ArenaForNormalPage();
-      normal_arena->SetIsLazySweeping(true);
-    }
-  }
   int page_count = 1;
   // TODO(bikineev): We should probably process pages in the reverse order. This
   // will leave more work for concurrent sweeper and reduce memory footprint
@@ -330,8 +321,6 @@ bool BaseArena::LazySweepWithDeadline(TimeTicks deadline) {
     if (page_count % kDeadlineCheckInterval == 0) {
       if (deadline <= CurrentTimeTicks()) {
         // Deadline has come.
-        if (normal_arena)
-          normal_arena->SetIsLazySweeping(false);
         return SweepingAndFinalizationCompleted();
       }
     }
@@ -343,8 +332,6 @@ bool BaseArena::LazySweepWithDeadline(TimeTicks deadline) {
     if (page_count % kDeadlineCheckInterval == 0) {
       if (deadline <= CurrentTimeTicks()) {
         // Deadline has come.
-        if (normal_arena)
-          normal_arena->SetIsLazySweeping(false);
         return SweepingAndFinalizationCompleted();
       }
     }
@@ -355,16 +342,12 @@ bool BaseArena::LazySweepWithDeadline(TimeTicks deadline) {
     if (page_count % kDeadlineCheckInterval == 0) {
       if (deadline <= CurrentTimeTicks()) {
         // Deadline has come.
-        if (normal_arena)
-          normal_arena->SetIsLazySweeping(false);
         return SweepingAndFinalizationCompleted();
       }
     }
     page_count++;
   }
 
-  if (normal_arena)
-    normal_arena->SetIsLazySweeping(false);
   return true;
 }
 
@@ -415,8 +398,7 @@ NormalPageArena::NormalPageArena(ThreadState* state, int index)
       current_allocation_point_(nullptr),
       remaining_allocation_size_(0),
       last_remaining_allocation_size_(0),
-      promptly_freed_size_(0),
-      is_lazy_sweeping_(false) {
+      promptly_freed_size_(0) {
   ClearFreeLists();
 }
 
@@ -827,7 +809,6 @@ Address NormalPageArena::AllocateFromFreeList(size_t allocation_size,
 Address NormalPageArena::LazySweepPages(size_t allocation_size,
                                         size_t gc_info_index) {
   DCHECK(!HasCurrentAllocationArea());
-  base::AutoReset<bool> is_lazy_sweeping(&is_lazy_sweeping_, true);
   Address result = nullptr;
   // First, process unfinalized pages as finalizing a page is faster than
   // sweeping.

third_party/blink/renderer/platform/heap/heap_page.h

@@ -900,9 +900,6 @@ class PLATFORM_EXPORT NormalPageArena final : public BaseArena {
     return header->PayloadEnd() == current_allocation_point_;
   }
 
-  bool IsLazySweeping() const { return is_lazy_sweeping_; }
-  void SetIsLazySweeping(bool sweeping) { is_lazy_sweeping_ = sweeping; }
-
   size_t ArenaSize();
   size_t FreeListSize();
 
@@ -957,8 +954,6 @@ class PLATFORM_EXPORT NormalPageArena final : public BaseArena {
   // zero before sweeping when clearing the free list and after coalescing.
   // It will increase for promptly freed objects on already swept pages.
   size_t promptly_freed_size_;
-
-  bool is_lazy_sweeping_;
 };
 
 class LargeObjectArena final : public BaseArena {