Backport http://code.google.com/p/v8/source/detail?r=5181 to 2.2....

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 5189)
+++ src/heap.cc	(working copy)
@@ -4111,7 +4111,7 @@
 }
 
 
-void Heap::RecordStats(HeapStats* stats) {
+void Heap::RecordStats(HeapStats* stats, bool take_snapshot) {
   *stats->start_marker = 0xDECADE00;
   *stats->end_marker = 0xDECADE01;
   *stats->new_space_size = new_space_.Size();
@@ -4128,6 +4128,23 @@
   *stats->cell_space_capacity = cell_space_->Capacity();
   *stats->lo_space_size = lo_space_->Size();
   GlobalHandles::RecordStats(stats);
+  *stats->memory_allocator_size = MemoryAllocator::Size();
+  *stats->memory_allocator_capacity =
+      MemoryAllocator::Size() + MemoryAllocator::Available();
+  if (take_snapshot) {
+    HeapIterator iterator;
+    for (HeapObject* obj = iterator.next();
+         obj != NULL;
+         obj = iterator.next()) {
+      // Note: snapshot won't be precise because IsFreeListNode returns true
+      // for any bytearray.
+      if (FreeListNode::IsFreeListNode(obj)) continue;
+      InstanceType type = obj->map()->instance_type();
+      ASSERT(0 <= type && type <= LAST_TYPE);
+      stats->objects_per_type[type]++;
+      stats->size_per_type[type] += obj->Size();
+    }
+  }
 }