Reland of "[heap] Parallel newspace evacuation, semispace copy, and compaction \o/"

src/heap/spaces.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include "src/allocation.h"
 #include "src/atomic-utils.h"
 #include "src/base/atomicops.h"
@@ skipping 2899 matching lines @@
   MUST_USE_RESULT HeapObject* SweepAndRetryAllocation(
       int size_in_bytes) override;
 };
 
 
 // A collection of |CompactionSpace|s used by a single compaction task.
 class CompactionSpaceCollection : public Malloced {
  public:
   explicit CompactionSpaceCollection(Heap* heap)
       : old_space_(heap, OLD_SPACE, Executability::NOT_EXECUTABLE),
-        code_space_(heap, CODE_SPACE, Executability::EXECUTABLE),
-        duration_(0.0),
-        bytes_compacted_(0) {}
+        code_space_(heap, CODE_SPACE, Executability::EXECUTABLE) {}
 
   CompactionSpace* Get(AllocationSpace space) {
     switch (space) {
       case OLD_SPACE:
         return &old_space_;
       case CODE_SPACE:
         return &code_space_;
       default:
         UNREACHABLE();
     }
     UNREACHABLE();
     return nullptr;
   }
 
-  void ReportCompactionProgress(double duration, intptr_t bytes_compacted) {
-    duration_ += duration;
-    bytes_compacted_ += bytes_compacted;
-  }
-
-  double duration() const { return duration_; }
-  intptr_t bytes_compacted() const { return bytes_compacted_; }
-
  private:
   CompactionSpace old_space_;
   CompactionSpace code_space_;
-
-  // Book keeping.
-  double duration_;
-  intptr_t bytes_compacted_;
 };
 
 
 // -----------------------------------------------------------------------------
 // Old object space (includes the old space of objects and code space)
 
 class OldSpace : public PagedSpace {
  public:
   // Creates an old space object. The constructor does not allocate pages
   // from OS.
@@ skipping 180 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_