Adding V8 api to get memory statistics of spaces in V8::Heap.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 28c84106df4c260cfbd2e96972a12efcd1f10964..5e56a5e0798c744c0b005e49d67dee982e10d564 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6966,6 +6966,24 @@ void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   heap_statistics->total_physical_size_ = heap->CommittedPhysicalMemory();
   heap_statistics->used_heap_size_ = heap->SizeOfObjects();
   heap_statistics->heap_size_limit_ = heap->MaxReserved();
+
+  HeapStatistics::SpaceStatistics new_space_stats(
+      heap->new_space()->Size(), heap->new_space()->CommittedMemory(),
+      heap->new_space()->Available());
+  heap_statistics->spaces_statistics().push_back(new_space_stats);
+
+  for (int space = i::AllocationSpace::FIRST_PAGED_SPACE;
+       space < i::AllocationSpace::LAST_PAGED_SPACE; space++) {
+    HeapStatistics::SpaceStatistics space_stats(
+        heap->paged_space(space)->Size(),

[rmcilroy, 2015/04/13 17:40:08]

This should be SizeOfObjects()

[ssid, 2015/04/14 16:59:16]

Done.

+        heap->paged_space(space)->CommittedMemory(),
+        heap->paged_space(space)->Available());
+    heap_statistics->spaces_statistics().push_back(space_stats);
+  }
+  HeapStatistics::SpaceStatistics lo_space_stats(

[rmcilroy, 2015/04/13 17:40:08]

nit - newline above

[ssid, 2015/04/14 16:59:16]

Done.

+      heap->lo_space()->Size(), heap->lo_space()->CommittedMemory(),
+      heap->lo_space()->Available());
+  heap_statistics->spaces_statistics().push_back(lo_space_stats);
 }