Debugger: remove duplicate heap iterations.

src/runtime/runtime-object.cc

 // Copyright 2014 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/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/debug/debug.h"
 #include "src/messages.h"
@@ skipping 246 matching lines @@
     return *result;
   }
   Handle<Object> result;
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result, JSObject::SetPrototype(obj, prototype, true));
   return *result;
 }
 
 
 RUNTIME_FUNCTION(Runtime_IsInPrototypeChain) {
-  HandleScope shs(isolate);
+  SealHandleScope shs(isolate);
   DCHECK(args.length() == 2);
   // See ECMA-262, section 15.3.5.3, page 88 (steps 5 - 8).
-  CONVERT_ARG_HANDLE_CHECKED(Object, O, 0);
-  CONVERT_ARG_HANDLE_CHECKED(Object, V, 1);
-  PrototypeIterator iter(isolate, V, PrototypeIterator::START_AT_RECEIVER);
-  while (true) {
-    iter.AdvanceIgnoringProxies();
-    if (iter.IsAtEnd()) return isolate->heap()->false_value();
-    if (iter.IsAtEnd(O)) return isolate->heap()->true_value();
-  }
+  CONVERT_ARG_CHECKED(Object, O, 0);
+  CONVERT_ARG_CHECKED(Object, V, 1);
+  return isolate->heap()->ToBoolean(V->HasInPrototypeChain(isolate, O));
 }
 
 
 // Enumerator used as indices into the array returned from GetOwnProperty
 enum PropertyDescriptorIndices {
   IS_ACCESSOR_INDEX,
   VALUE_INDEX,
   GETTER_INDEX,
   SETTER_INDEX,
   WRITABLE_INDEX,
@@ skipping 1149 matching lines @@
   Handle<JSReceiver> receiver;
   if (JSReceiver::ToObject(isolate, object).ToHandle(&receiver)) {
     return *receiver;
   }
   THROW_NEW_ERROR_RETURN_FAILURE(
       isolate, NewTypeError(MessageTemplate::kUndefinedOrNullToObject));
 }
 
 }  // namespace internal
 }  // namespace v8