[heap] Use PageParallelJob for parallel evacuation

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index 7890de345d6f14221c0368841ab6440160958724..32513b7c960b4d78f606eeade15fa0987a5943ed 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -302,7 +302,6 @@ class MemoryChunk {
     EVACUATION_CANDIDATE,
     RESCAN_ON_EVACUATION,
     NEVER_EVACUATE,  // May contain immortal immutables.
-    POPULAR_PAGE,    // Slots buffer of this page overflowed on the previous GC.
 
     // Large objects can have a progress bar in their page header. These object
     // are scanned in increments and will be kept black while being scanned.
@@ -331,19 +330,6 @@ class MemoryChunk {
     NUM_MEMORY_CHUNK_FLAGS
   };
 
-  // |kCompactionDone|: Initial compaction state of a |MemoryChunk|.
-  // |kCompactingInProgress|:  Parallel compaction is currently in progress.
-  // |kCompactingFinalize|: Parallel compaction is done but the chunk needs to
-  //   be finalized.
-  // |kCompactingAborted|: Parallel compaction has been aborted, which should
-  //   for now only happen in OOM scenarios.
-  enum ParallelCompactingState {
-    kCompactingDone,
-    kCompactingInProgress,
-    kCompactingFinalize,
-    kCompactingAborted,
-  };
-
   // |kSweepingDone|: The page state when sweeping is complete or sweeping must
   //   not be performed on that page. Sweeper threads that are done with their
   //   work will set this value and not touch the page anymore.
@@ -403,8 +389,7 @@ class MemoryChunk {
       kIntptrSize         // intptr_t write_barrier_counter_
       + kPointerSize      // AtomicValue high_water_mark_
       + kPointerSize      // base::Mutex* mutex_
-      + kPointerSize      // base::AtomicWord parallel_sweeping_
-      + kPointerSize      // AtomicValue parallel_compaction_
+      + kPointerSize      // base::AtomicWord concurrent_sweeping_
       + 2 * kPointerSize  // AtomicNumber free-list statistics
       + kPointerSize      // AtomicValue next_chunk_
       + kPointerSize;     // AtomicValue prev_chunk_
@@ -471,10 +456,6 @@ class MemoryChunk {
     return concurrent_sweeping_;
   }
 
-  AtomicValue<ParallelCompactingState>& parallel_compaction_state() {
-    return parallel_compaction_;
-  }
-
   // Manage live byte count, i.e., count of bytes in black objects.
   inline void ResetLiveBytes();
   inline void IncrementLiveBytes(int by);
@@ -701,7 +682,6 @@ class MemoryChunk {
   base::Mutex* mutex_;
 
   AtomicValue<ConcurrentSweepingState> concurrent_sweeping_;
-  AtomicValue<ParallelCompactingState> parallel_compaction_;
 
   // PagedSpace free-list statistics.
   AtomicNumber<intptr_t> available_in_free_list_;