Reland 'Additional HandleScopes to limit Handle consumption.'

src/handles-inl.h

 // Copyright 2006-2008 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.
 //
 
 #ifndef V8_HANDLES_INL_H_
 #define V8_HANDLES_INL_H_
 
 #include "src/api.h"
 #include "src/handles.h"
@@ skipping 74 matching lines @@
 HandleScope::HandleScope(Isolate* isolate) {
   HandleScopeData* current = isolate->handle_scope_data();
   isolate_ = isolate;
   prev_next_ = current->next;
   prev_limit_ = current->limit;
   current->level++;
 }
 
 
 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
 }
 
 
 void HandleScope::CloseScope(Isolate* isolate,
                              Object** prev_next,
                              Object** prev_limit) {
   HandleScopeData* current = isolate->handle_scope_data();
 
   std::swap(current->next, prev_next);
   current->level--;
@@ skipping 68 matching lines @@
   current->level = level_;
   DCHECK_EQ(current->next, current->limit);
   current->limit = limit_;
 }
 
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_HANDLES_INL_H_