Reland 'Additional HandleScopes to limit Handle consumption.'

src/handles-inl.h

Index: src/handles-inl.h
diff --git a/src/handles-inl.h b/src/handles-inl.h
index 34b3f32d960415bd93dd3cbe1c8f5d9178ba8399..3022f288a3919230c955c01c90d5773d731fac6d 100644
--- a/src/handles-inl.h
+++ b/src/handles-inl.h
@@ -92,7 +92,19 @@ HandleScope::HandleScope(Isolate* isolate) {
 
 
 HandleScope::~HandleScope() {
-  CloseScope(isolate_, prev_next_, prev_limit_);
+#ifdef DEBUG
+  if (FLAG_check_handle_count) {
+    int before = NumberOfHandles(isolate_);
+    CloseScope(isolate_, prev_next_, prev_limit_);
+    int after = NumberOfHandles(isolate_);
+    DCHECK(after - before < kCheckHandleThreshold);
+    DCHECK(before < kCheckHandleThreshold);
+  } else {
+#endif  // DEBUG
+    CloseScope(isolate_, prev_next_, prev_limit_);
+#ifdef DEBUG
+  }
+#endif  // DEBUG
 }