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

src/heap/heap.cc

 // Copyright 2012 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.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 434 matching lines @@
 intptr_t Heap::SizeOfObjects() {
   intptr_t total = 0;
   AllSpaces spaces(this);
   for (Space* space = spaces.next(); space != NULL; space = spaces.next()) {
     total += space->SizeOfObjects();
   }
   return total;
 }
 
 
+const char* Heap::GetSpaceName(int idx) {
+  switch (idx) {
+    case NEW_SPACE:
+      return "new_space";
+    case OLD_SPACE:
+      return "old_space";
+    case MAP_SPACE:
+      return "map_space";
+    case CODE_SPACE:
+      return "code_space";
+    case LO_SPACE:
+      return "large_object_space";
+    default:
+      UNREACHABLE();
+  }
+  return nullptr;
+}
+
+
 void Heap::ClearAllICsByKind(Code::Kind kind) {
   HeapObjectIterator it(code_space());
 
   for (Object* object = it.Next(); object != NULL; object = it.Next()) {
     Code* code = Code::cast(object);
     Code::Kind current_kind = code->kind();
     if (current_kind == Code::FUNCTION ||
         current_kind == Code::OPTIMIZED_FUNCTION) {
       code->ClearInlineCaches(kind);
     }
@@ skipping 5844 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal