Add information about memory allocator's size and capacity and heap snapshot into heap stats.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 2994a6d6e0440a873d55e54fbdbc24a79f85d1f7..d53824f006323562e4c1af8a1b0e4c0cb1993ecb 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -981,7 +981,7 @@ class Heap : public AllStatic {
   static RootListIndex RootIndexForExternalArrayType(
       ExternalArrayType array_type);
 
-  static void RecordStats(HeapStats* stats);
+  static void RecordStats(HeapStats* stats, bool take_snapshot = false);
 
   static Scavenger GetScavenger(int instance_type, int instance_size);
 
@@ -1324,26 +1324,30 @@ class Heap : public AllStatic {
 
 class HeapStats {
  public:
-  int* start_marker;
-  int* new_space_size;
-  int* new_space_capacity;
-  int* old_pointer_space_size;
-  int* old_pointer_space_capacity;
-  int* old_data_space_size;
-  int* old_data_space_capacity;
-  int* code_space_size;
-  int* code_space_capacity;
-  int* map_space_size;
-  int* map_space_capacity;
-  int* cell_space_size;
-  int* cell_space_capacity;
-  int* lo_space_size;
-  int* global_handle_count;
-  int* weak_global_handle_count;
-  int* pending_global_handle_count;
-  int* near_death_global_handle_count;
-  int* destroyed_global_handle_count;
-  int* end_marker;
+  int* start_marker;                    //  0
+  int* new_space_size;                  //  1
+  int* new_space_capacity;              //  2
+  int* old_pointer_space_size;          //  3
+  int* old_pointer_space_capacity;      //  4
+  int* old_data_space_size;             //  5
+  int* old_data_space_capacity;         //  6
+  int* code_space_size;                 //  7
+  int* code_space_capacity;             //  8
+  int* map_space_size;                  //  9
+  int* map_space_capacity;              // 10
+  int* cell_space_size;                 // 11
+  int* cell_space_capacity;             // 12
+  int* lo_space_size;                   // 13
+  int* global_handle_count;             // 14
+  int* weak_global_handle_count;        // 15
+  int* pending_global_handle_count;     // 16
+  int* near_death_global_handle_count;  // 17
+  int* destroyed_global_handle_count;   // 18
+  int* memory_allocator_size;           // 19
+  int* memory_allocator_capacity;       // 20
+  int* objects_per_type;                // 21
+  int* size_per_type;                   // 22
+  int* end_marker;                      // 23
 };