diff --git a/src/spaces.h b/src/spaces.h
index 6165255..bd939d1 100644
--- a/src/spaces.h
+++ b/src/spaces.h
@@ -34,6 +34,8 @@
 namespace v8 {
 namespace internal {
 
+class Isolate;
+
 // -----------------------------------------------------------------------------
 // Heap structures:
 //
@@ -241,7 +243,7 @@
   static const intptr_t kPageAlignmentMask = (1 << kPageSizeBits) - 1;
 
   static const int kPageHeaderSize = kPointerSize + kPointerSize + kIntSize +
-    kIntSize + kPointerSize;
+    kIntSize + kPointerSize + kPointerSize;
 
   // The start offset of the object area in a page. Aligned to both maps and
   // code alignment to be suitable for both.
@@ -286,7 +288,7 @@
   // This invariant guarantees that after flipping flag meaning at the
   // beginning of scavenge all pages in use will be marked as having valid
   // watermark.
-  static inline void FlipMeaningOfInvalidatedWatermarkFlag();
+  static inline void FlipMeaningOfInvalidatedWatermarkFlag(Heap* heap);
 
   // Returns true if the page allocation watermark was not altered during
   // scavenge.
@@ -312,11 +314,6 @@
   STATIC_CHECK(kBitsPerInt - kAllocationWatermarkOffsetShift >=
                kAllocationWatermarkOffsetBits);
 
-  // This field contains the meaning of the WATERMARK_INVALIDATED flag.
-  // Instead of clearing this flag from all pages we just flip
-  // its meaning at the beginning of a scavenge.
-  static intptr_t watermark_invalidated_mark_;
-
   //---------------------------------------------------------------------------
   // Page header description.
   //
@@ -353,6 +350,8 @@
   // During scavenge collection this field is used to store allocation watermark
   // if it is altered during scavenge.
   Address mc_first_forwarded;
+
+  Heap* heap_;
 };
 
 
@@ -360,11 +359,13 @@
 // Space is the abstract superclass for all allocation spaces.
 class Space : public Malloced {
  public:
-  Space(AllocationSpace id, Executability executable)
-      : id_(id), executable_(executable) {}
+  Space(Heap* heap, AllocationSpace id, Executability executable)
+      : heap_(heap), id_(id), executable_(executable) {}
 
   virtual ~Space() {}
 
+  Heap* heap() const { return heap_; }
+
   // Does the space need executable memory?
   Executability executable() { return executable_; }
 
@@ -397,6 +398,7 @@
   virtual bool ReserveSpace(int bytes) = 0;
 
  private:
+  Heap* heap_;
   AllocationSpace id_;
   Executability executable_;
 };
@@ -409,19 +411,19 @@
 // displacements cover the entire 4GB virtual address space.  On 64-bit
 // platforms, we support this using the CodeRange object, which reserves and
 // manages a range of virtual memory.
-class CodeRange : public AllStatic {
+class CodeRange {
  public:
   // Reserves a range of virtual memory, but does not commit any of it.
   // Can only be called once, at heap initialization time.
   // Returns false on failure.
-  static bool Setup(const size_t requested_size);
+  bool Setup(const size_t requested_size);
 
   // Frees the range of virtual memory, and frees the data structures used to
   // manage it.
-  static void TearDown();
+  void TearDown();
 
-  static bool exists() { return code_range_ != NULL; }
-  static bool contains(Address address) {
+  bool exists() { return code_range_ != NULL; }
+  bool contains(Address address) {
     if (code_range_ == NULL) return false;
     Address start = static_cast<Address>(code_range_->address());
     return start <= address && address < start + code_range_->size();
@@ -430,13 +432,15 @@
   // Allocates a chunk of memory from the large-object portion of
   // the code range.  On platforms with no separate code range, should
   // not be called.
-  MUST_USE_RESULT static void* AllocateRawMemory(const size_t requested,
-                                                 size_t* allocated);
-  static void FreeRawMemory(void* buf, size_t length);
+  MUST_USE_RESULT void* AllocateRawMemory(const size_t requested,
+                                          size_t* allocated);
+  void FreeRawMemory(void* buf, size_t length);
 
  private:
+  CodeRange();
+
   // The reserved range of virtual memory that all code objects are put in.
-  static VirtualMemory* code_range_;
+  VirtualMemory* code_range_;
   // Plain old data class, just a struct plus a constructor.
   class FreeBlock {
    public:
@@ -452,20 +456,26 @@
   // Freed blocks of memory are added to the free list.  When the allocation
   // list is exhausted, the free list is sorted and merged to make the new
   // allocation list.
-  static List<FreeBlock> free_list_;
+  List<FreeBlock> free_list_;
   // Memory is allocated from the free blocks on the allocation list.
   // The block at current_allocation_block_index_ is the current block.
-  static List<FreeBlock> allocation_list_;
-  static int current_allocation_block_index_;
+  List<FreeBlock> allocation_list_;
+  int current_allocation_block_index_;
 
   // Finds a block on the allocation list that contains at least the
   // requested amount of memory.  If none is found, sorts and merges
   // the existing free memory blocks, and searches again.
   // If none can be found, terminates V8 with FatalProcessOutOfMemory.
-  static void GetNextAllocationBlock(size_t requested);
+  void GetNextAllocationBlock(size_t requested);
   // Compares the start addresses of two free blocks.
   static int CompareFreeBlockAddress(const FreeBlock* left,
                                      const FreeBlock* right);
+
+  friend class Isolate;
+
+  Isolate* isolate_;
+
+  DISALLOW_COPY_AND_ASSIGN(CodeRange);
 };
 
 
@@ -493,14 +503,14 @@
 //
 
 
-class MemoryAllocator : public AllStatic {
+class MemoryAllocator {
  public:
   // Initializes its internal bookkeeping structures.
   // Max capacity of the total space and executable memory limit.
-  static bool Setup(intptr_t max_capacity, intptr_t capacity_executable);
+  bool Setup(intptr_t max_capacity, intptr_t capacity_executable);
 
   // Deletes valid chunks.
-  static void TearDown();
+  void TearDown();
 
   // Reserves an initial address range of virtual memory to be split between
   // the two new space semispaces, the old space, and the map space.  The
@@ -511,7 +521,7 @@
   // address of the initial chunk if successful, with the side effect of
   // setting the initial chunk, or else NULL if unsuccessful and leaves the
   // initial chunk NULL.
-  static void* ReserveInitialChunk(const size_t requested);
+  void* ReserveInitialChunk(const size_t requested);
 
   // Commits pages from an as-yet-unmanaged block of virtual memory into a
   // paged space.  The block should be part of the initial chunk reserved via
@@ -520,24 +530,24 @@
   // address is non-null and that it is big enough to hold at least one
   // page-aligned page.  The call always succeeds, and num_pages is always
   // greater than zero.
-  static Page* CommitPages(Address start, size_t size, PagedSpace* owner,
-                           int* num_pages);
+  Page* CommitPages(Address start, size_t size, PagedSpace* owner,
+                    int* num_pages);
 
   // Commit a contiguous block of memory from the initial chunk.  Assumes that
   // the address is not NULL, the size is greater than zero, and that the
   // block is contained in the initial chunk.  Returns true if it succeeded
   // and false otherwise.
-  static bool CommitBlock(Address start, size_t size, Executability executable);
+  bool CommitBlock(Address start, size_t size, Executability executable);
 
   // Uncommit a contiguous block of memory [start..(start+size)[.
   // start is not NULL, the size is greater than zero, and the
   // block is contained in the initial chunk.  Returns true if it succeeded
   // and false otherwise.
-  static bool UncommitBlock(Address start, size_t size);
+  bool UncommitBlock(Address start, size_t size);
 
   // Zaps a contiguous block of memory [start..(start+size)[ thus
   // filling it up with a recognizable non-NULL bit pattern.
-  static void ZapBlock(Address start, size_t size);
+  void ZapBlock(Address start, size_t size);
 
   // Attempts to allocate the requested (non-zero) number of pages from the
   // OS.  Fewer pages might be allocated than requested. If it fails to
@@ -548,8 +558,8 @@
   // number of allocated pages is returned in the output parameter
   // allocated_pages.  If the PagedSpace owner is executable and there is
   // a code range, the pages are allocated from the code range.
-  static Page* AllocatePages(int requested_pages, int* allocated_pages,
-                             PagedSpace* owner);
+  Page* AllocatePages(int requested_pages, int* allocated_pages,
+                      PagedSpace* owner);
 
   // Frees pages from a given page and after. Requires pages to be
   // linked in chunk-order (see comment for class).
@@ -558,10 +568,10 @@
   // Otherwise, the function searches a page after 'p' that is
   // the first page of a chunk. Pages after the found page
   // are freed and the function returns 'p'.
-  static Page* FreePages(Page* p);
+  Page* FreePages(Page* p);
 
   // Frees all pages owned by given space.
-  static void FreeAllPages(PagedSpace* space);
+  void FreeAllPages(PagedSpace* space);
 
   // Allocates and frees raw memory of certain size.
   // These are just thin wrappers around OS::Allocate and OS::Free,
@@ -569,96 +579,83 @@
   // If the flag is EXECUTABLE and a code range exists, the requested
   // memory is allocated from the code range.  If a code range exists
   // and the freed memory is in it, the code range manages the freed memory.
-  MUST_USE_RESULT static void* AllocateRawMemory(const size_t requested,
-                                                 size_t* allocated,
-                                                 Executability executable);
-  static void FreeRawMemory(void* buf,
-                            size_t length,
-                            Executability executable);
-  static void PerformAllocationCallback(ObjectSpace space,
-                                        AllocationAction action,
-                                        size_t size);
+  MUST_USE_RESULT void* AllocateRawMemory(const size_t requested,
+                                          size_t* allocated,
+                                          Executability executable);
+  void FreeRawMemory(void* buf,
+                     size_t length,
+                     Executability executable);
+  void PerformAllocationCallback(ObjectSpace space,
+                                 AllocationAction action,
+                                 size_t size);
 
-  static void AddMemoryAllocationCallback(MemoryAllocationCallback callback,
-                                          ObjectSpace space,
-                                          AllocationAction action);
-  static void RemoveMemoryAllocationCallback(
-      MemoryAllocationCallback callback);
-  static bool MemoryAllocationCallbackRegistered(
-      MemoryAllocationCallback callback);
+  void AddMemoryAllocationCallback(MemoryAllocationCallback callback,
+                                   ObjectSpace space,
+                                   AllocationAction action);
+  void RemoveMemoryAllocationCallback(MemoryAllocationCallback callback);
+  bool MemoryAllocationCallbackRegistered(MemoryAllocationCallback callback);
 
   // Returns the maximum available bytes of heaps.
-  static intptr_t Available() {
-    return capacity_ < size_ ? 0 : capacity_ - size_;
-  }
+  intptr_t Available() { return capacity_ < size_ ? 0 : capacity_ - size_; }
 
   // Returns allocated spaces in bytes.
-  static intptr_t Size() { return size_; }
+  intptr_t Size() { return size_; }
 
   // Returns the maximum available executable bytes of heaps.
-  static intptr_t AvailableExecutable() {
+  intptr_t AvailableExecutable() {
     if (capacity_executable_ < size_executable_) return 0;
     return capacity_executable_ - size_executable_;
   }
 
   // Returns allocated executable spaces in bytes.
-  static intptr_t SizeExecutable() { return size_executable_; }
+  intptr_t SizeExecutable() { return size_executable_; }
 
   // Returns maximum available bytes that the old space can have.
-  static intptr_t MaxAvailable() {
+  intptr_t MaxAvailable() {
     return (Available() / Page::kPageSize) * Page::kObjectAreaSize;
   }
 
-  // Sanity check on a pointer.
-  static bool SafeIsInAPageChunk(Address addr);
-
   // Links two pages.
-  static inline void SetNextPage(Page* prev, Page* next);
+  inline void SetNextPage(Page* prev, Page* next);
 
   // Returns the next page of a given page.
-  static inline Page* GetNextPage(Page* p);
+  inline Page* GetNextPage(Page* p);
 
   // Checks whether a page belongs to a space.
-  static inline bool IsPageInSpace(Page* p, PagedSpace* space);
+  inline bool IsPageInSpace(Page* p, PagedSpace* space);
 
   // Returns the space that owns the given page.
-  static inline PagedSpace* PageOwner(Page* page);
+  inline PagedSpace* PageOwner(Page* page);
 
   // Finds the first/last page in the same chunk as a given page.
-  static Page* FindFirstPageInSameChunk(Page* p);
-  static Page* FindLastPageInSameChunk(Page* p);
+  Page* FindFirstPageInSameChunk(Page* p);
+  Page* FindLastPageInSameChunk(Page* p);
 
   // Relinks list of pages owned by space to make it chunk-ordered.
   // Returns new first and last pages of space.
   // Also returns last page in relinked list which has WasInUsedBeforeMC
   // flag set.
-  static void RelinkPageListInChunkOrder(PagedSpace* space,
-                                         Page** first_page,
-                                         Page** last_page,
-                                         Page** last_page_in_use);
+  void RelinkPageListInChunkOrder(PagedSpace* space,
+                                  Page** first_page,
+                                  Page** last_page,
+                                  Page** last_page_in_use);
 
 #ifdef ENABLE_HEAP_PROTECTION
   // Protect/unprotect a block of memory by marking it read-only/writable.
-  static inline void Protect(Address start, size_t size);
-  static inline void Unprotect(Address start, size_t size,
-                               Executability executable);
+  inline void Protect(Address start, size_t size);
+  inline void Unprotect(Address start, size_t size,
+                        Executability executable);
 
   // Protect/unprotect a chunk given a page in the chunk.
-  static inline void ProtectChunkFromPage(Page* page);
-  static inline void UnprotectChunkFromPage(Page* page);
+  inline void ProtectChunkFromPage(Page* page);
+  inline void UnprotectChunkFromPage(Page* page);
 #endif
 
 #ifdef DEBUG
   // Reports statistic info of the space.
-  static void ReportStatistics();
+  void ReportStatistics();
 #endif
 
-  static void AddToAllocatedChunks(Address addr, intptr_t size);
-  static void RemoveFromAllocatedChunks(Address addr, intptr_t size);
-  // Note: This only checks the regular chunks, not the odd-sized initial
-  // chunk.
-  static bool InAllocatedChunks(Address addr);
-
   // Due to encoding limitation, we can only have 8K chunks.
   static const int kMaxNofChunks = 1 << kPageSizeBits;
   // If a chunk has at least 16 pages, the maximum heap size is about
@@ -678,29 +675,21 @@
 #endif
 
  private:
+  MemoryAllocator();
+
   static const int kChunkSize = kPagesPerChunk * Page::kPageSize;
   static const int kChunkSizeLog2 = kPagesPerChunkLog2 + kPageSizeBits;
-  static const int kChunkTableTopLevelEntries =
-      1 << (sizeof(intptr_t) * kBitsPerByte - kChunkSizeLog2 -
-          (kChunkTableLevels - 1) * kChunkTableBitsPerLevel);
-
-  // The chunks are not chunk-size aligned so for a given chunk-sized area of
-  // memory there can be two chunks that cover it.
-  static const int kChunkTableFineGrainedWordsPerEntry = 2;
-  static const uintptr_t kUnusedChunkTableEntry = 0;
 
   // Maximum space size in bytes.
-  static intptr_t capacity_;
+  intptr_t capacity_;
   // Maximum subset of capacity_ that can be executable
-  static intptr_t capacity_executable_;
-
-  // Top level table to track whether memory is part of a chunk or not.
-  static uintptr_t chunk_table_[kChunkTableTopLevelEntries];
+  intptr_t capacity_executable_;
 
   // Allocated space size in bytes.
-  static intptr_t size_;
+  intptr_t size_;
+
   // Allocated executable space size in bytes.
-  static intptr_t size_executable_;
+  intptr_t size_executable_;
 
   struct MemoryAllocationCallbackRegistration {
     MemoryAllocationCallbackRegistration(MemoryAllocationCallback callback,
@@ -713,11 +702,11 @@
     AllocationAction action;
   };
   // A List of callback that are triggered when memory is allocated or free'd
-  static List<MemoryAllocationCallbackRegistration>
+  List<MemoryAllocationCallbackRegistration>
       memory_allocation_callbacks_;
 
   // The initial chunk of virtual memory.
-  static VirtualMemory* initial_chunk_;
+  VirtualMemory* initial_chunk_;
 
   // Allocated chunk info: chunk start address, chunk size, and owning space.
   class ChunkInfo BASE_EMBEDDED {
@@ -725,7 +714,8 @@
     ChunkInfo() : address_(NULL),
                   size_(0),
                   owner_(NULL),
-                  executable_(NOT_EXECUTABLE) {}
+                  executable_(NOT_EXECUTABLE),
+                  owner_identity_(FIRST_SPACE) {}
     inline void init(Address a, size_t s, PagedSpace* o);
     Address address() { return address_; }
     size_t size() { return size_; }
@@ -733,74 +723,60 @@
     // We save executability of the owner to allow using it
     // when collecting stats after the owner has been destroyed.
     Executability executable() const { return executable_; }
+    AllocationSpace owner_identity() const { return owner_identity_; }
 
    private:
     Address address_;
     size_t size_;
     PagedSpace* owner_;
     Executability executable_;
+    AllocationSpace owner_identity_;
   };
 
   // Chunks_, free_chunk_ids_ and top_ act as a stack of free chunk ids.
-  static List<ChunkInfo> chunks_;
-  static List<int> free_chunk_ids_;
-  static int max_nof_chunks_;
-  static int top_;
+  List<ChunkInfo> chunks_;
+  List<int> free_chunk_ids_;
+  int max_nof_chunks_;
+  int top_;
 
   // Push/pop a free chunk id onto/from the stack.
-  static void Push(int free_chunk_id);
-  static int Pop();
-  static bool OutOfChunkIds() { return top_ == 0; }
+  void Push(int free_chunk_id);
+  int Pop();
+  bool OutOfChunkIds() { return top_ == 0; }
 
   // Frees a chunk.
-  static void DeleteChunk(int chunk_id);
-
-  // Helpers to maintain and query the chunk tables.
-  static void AddChunkUsingAddress(
-      uintptr_t chunk_start,        // Where the chunk starts.
-      uintptr_t chunk_index_base);  // Used to place the chunk in the tables.
-  static void RemoveChunkFoundUsingAddress(
-      uintptr_t chunk_start,        // Where the chunk starts.
-      uintptr_t chunk_index_base);  // Used to locate the entry in the tables.
-  // Controls whether the lookup creates intermediate levels of tables as
-  // needed.
-  enum CreateTables { kDontCreateTables, kCreateTablesAsNeeded };
-  static uintptr_t* AllocatedChunksFinder(uintptr_t* table,
-                                          uintptr_t address,
-                                          int bit_position,
-                                          CreateTables create_as_needed);
-  static void FreeChunkTables(uintptr_t* array, int length, int level);
-  static int FineGrainedIndexForAddress(uintptr_t address) {
-    int index = ((address >> kChunkSizeLog2) &
-        ((1 << kChunkTableBitsPerLevel) - 1));
-    return index * kChunkTableFineGrainedWordsPerEntry;
-  }
-
+  void DeleteChunk(int chunk_id);
 
   // Basic check whether a chunk id is in the valid range.
-  static inline bool IsValidChunkId(int chunk_id);
+  inline bool IsValidChunkId(int chunk_id);
 
   // Checks whether a chunk id identifies an allocated chunk.
-  static inline bool IsValidChunk(int chunk_id);
+  inline bool IsValidChunk(int chunk_id);
 
   // Returns the chunk id that a page belongs to.
-  static inline int GetChunkId(Page* p);
+  inline int GetChunkId(Page* p);
 
   // True if the address lies in the initial chunk.
-  static inline bool InInitialChunk(Address address);
+  inline bool InInitialChunk(Address address);
 
   // Initializes pages in a chunk. Returns the first page address.
   // This function and GetChunkId() are provided for the mark-compact
   // collector to rebuild page headers in the from space, which is
   // used as a marking stack and its page headers are destroyed.
-  static Page* InitializePagesInChunk(int chunk_id, int pages_in_chunk,
-                                      PagedSpace* owner);
+  Page* InitializePagesInChunk(int chunk_id, int pages_in_chunk,
+                               PagedSpace* owner);
 
-  static Page* RelinkPagesInChunk(int chunk_id,
-                                  Address chunk_start,
-                                  size_t chunk_size,
-                                  Page* prev,
-                                  Page** last_page_in_use);
+  Page* RelinkPagesInChunk(int chunk_id,
+                           Address chunk_start,
+                           size_t chunk_size,
+                           Page* prev,
+                           Page** last_page_in_use);
+
+  friend class Isolate;
+
+  Isolate* isolate_;
+
+  DISALLOW_COPY_AND_ASSIGN(MemoryAllocator);
 };
 
 
@@ -1048,7 +1024,8 @@
 class PagedSpace : public Space {
  public:
   // Creates a space with a maximum capacity, and an id.
-  PagedSpace(intptr_t max_capacity,
+  PagedSpace(Heap* heap,
+             intptr_t max_capacity,
              AllocationSpace id,
              Executability executable);
 
@@ -1341,7 +1318,7 @@
 class SemiSpace : public Space {
  public:
   // Constructor.
-  SemiSpace() :Space(NEW_SPACE, NOT_EXECUTABLE) {
+  explicit SemiSpace(Heap* heap) : Space(heap, NEW_SPACE, NOT_EXECUTABLE) {
     start_ = NULL;
     age_mark_ = NULL;
   }
@@ -1508,7 +1485,10 @@
 class NewSpace : public Space {
  public:
   // Constructor.
-  NewSpace() : Space(NEW_SPACE, NOT_EXECUTABLE) {}
+  explicit NewSpace(Heap* heap)
+    : Space(heap, NEW_SPACE, NOT_EXECUTABLE),
+      to_space_(heap),
+      from_space_(heap) {}
 
   // Sets up the new space using the given chunk.
   bool Setup(Address start, int size);
@@ -1741,11 +1721,11 @@
   // function also writes a map to the first word of the block so that it
   // looks like a heap object to the garbage collector and heap iteration
   // functions.
-  void set_size(int size_in_bytes);
+  void set_size(Heap* heap, int size_in_bytes);
 
   // Accessors for the next field.
-  inline Address next();
-  inline void set_next(Address next);
+  inline Address next(Heap* heap);
+  inline void set_next(Heap* heap, Address next);
 
  private:
   static const int kNextOffset = POINTER_SIZE_ALIGN(ByteArray::kHeaderSize);
@@ -1757,7 +1737,7 @@
 // The free list for the old space.
 class OldSpaceFreeList BASE_EMBEDDED {
  public:
-  explicit OldSpaceFreeList(AllocationSpace owner);
+  OldSpaceFreeList(Heap* heap, AllocationSpace owner);
 
   // Clear the free list.
   void Reset();
@@ -1787,6 +1767,8 @@
   static const int kMinBlockSize = 2 * kPointerSize;
   static const int kMaxBlockSize = Page::kMaxHeapObjectSize;
 
+  Heap* heap_;
+
   // The identity of the owning space, for building allocation Failure
   // objects.
   AllocationSpace owner_;
@@ -1861,7 +1843,7 @@
 // The free list for the map space.
 class FixedSizeFreeList BASE_EMBEDDED {
  public:
-  FixedSizeFreeList(AllocationSpace owner, int object_size);
+  FixedSizeFreeList(Heap* heap, AllocationSpace owner, int object_size);
 
   // Clear the free list.
   void Reset();
@@ -1882,6 +1864,9 @@
   void MarkNodes();
 
  private:
+
+  Heap* heap_;
+
   // Available bytes on the free list.
   intptr_t available_;
 
@@ -1909,10 +1894,12 @@
  public:
   // Creates an old space object with a given maximum capacity.
   // The constructor does not allocate pages from OS.
-  explicit OldSpace(intptr_t max_capacity,
-                    AllocationSpace id,
-                    Executability executable)
-      : PagedSpace(max_capacity, id, executable), free_list_(id) {
+  OldSpace(Heap* heap,
+           intptr_t max_capacity,
+           AllocationSpace id,
+           Executability executable)
+      : PagedSpace(heap, max_capacity, id, executable),
+        free_list_(heap, id) {
     page_extra_ = 0;
   }
 
@@ -1981,14 +1968,15 @@
 
 class FixedSpace : public PagedSpace {
  public:
-  FixedSpace(intptr_t max_capacity,
+  FixedSpace(Heap* heap,
+             intptr_t max_capacity,
              AllocationSpace id,
              int object_size_in_bytes,
              const char* name)
-      : PagedSpace(max_capacity, id, NOT_EXECUTABLE),
+      : PagedSpace(heap, max_capacity, id, NOT_EXECUTABLE),
         object_size_in_bytes_(object_size_in_bytes),
         name_(name),
-        free_list_(id, object_size_in_bytes) {
+        free_list_(heap, id, object_size_in_bytes) {
     page_extra_ = Page::kObjectAreaSize % object_size_in_bytes;
   }
 
@@ -2059,8 +2047,11 @@
 class MapSpace : public FixedSpace {
  public:
   // Creates a map space object with a maximum capacity.
-  MapSpace(intptr_t max_capacity, int max_map_space_pages, AllocationSpace id)
-      : FixedSpace(max_capacity, id, Map::kSize, "map"),
+  MapSpace(Heap* heap,
+           intptr_t max_capacity,
+           int max_map_space_pages,
+           AllocationSpace id)
+      : FixedSpace(heap, max_capacity, id, Map::kSize, "map"),
         max_map_space_pages_(max_map_space_pages) {
     ASSERT(max_map_space_pages < kMaxMapPageIndex);
   }
@@ -2170,8 +2161,9 @@
 class CellSpace : public FixedSpace {
  public:
   // Creates a property cell space object with a maximum capacity.
-  CellSpace(intptr_t max_capacity, AllocationSpace id)
-      : FixedSpace(max_capacity, id, JSGlobalPropertyCell::kSize, "cell") {}
+  CellSpace(Heap* heap, intptr_t max_capacity, AllocationSpace id)
+      : FixedSpace(heap, max_capacity, id, JSGlobalPropertyCell::kSize, "cell")
+  {}
 
  protected:
 #ifdef DEBUG
@@ -2246,7 +2238,7 @@
 
 class LargeObjectSpace : public Space {
  public:
-  explicit LargeObjectSpace(AllocationSpace id);
+  LargeObjectSpace(Heap* heap, AllocationSpace id);
   virtual ~LargeObjectSpace() {}
 
   // Initializes internal data structures.
@@ -2263,9 +2255,7 @@
   MUST_USE_RESULT MaybeObject* AllocateRawFixedArray(int size_in_bytes);
 
   // Available bytes for objects in this space.
-  intptr_t Available() {
-    return LargeObjectChunk::ObjectSizeFor(MemoryAllocator::Available());
-  }
+  inline intptr_t Available();
 
   virtual intptr_t Size() {
     return size_;
@@ -2357,6 +2347,22 @@
 };
 
 
+#ifdef DEBUG
+struct CommentStatistic {
+  const char* comment;
+  int size;
+  int count;
+  void Clear() {
+    comment = NULL;
+    size = 0;
+    count = 0;
+  }
+  // Must be small, since an iteration is used for lookup.
+  static const int kMaxComments = 64;
+};
+#endif
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_SPACES_H_