[ic] Don't check full prototype chain if name is a private symbol.

src/prototype.h

 // 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.
 
 #ifndef V8_PROTOTYPE_H_
 #define V8_PROTOTYPE_H_
 
 #include "src/isolate.h"
 #include "src/objects.h"
 
@@ skipping 35 matching lines @@
                     WhereToStart where_to_start = kStartAtPrototype,
                     WhereToEnd where_to_end = END_AT_NULL)
       : isolate_(isolate),
         object_(receiver),
         where_to_end_(where_to_end),
         is_at_end_(false),
         seen_proxies_(0) {
     if (where_to_start == kStartAtPrototype) Advance();
   }
 
-  explicit PrototypeIterator(Map* receiver_map)
+  explicit PrototypeIterator(Map* receiver_map,
+                             WhereToEnd where_to_end = END_AT_NULL)
       : isolate_(receiver_map->GetIsolate()),
         object_(receiver_map->GetPrototypeChainRootMap(isolate_)->prototype()),
-        where_to_end_(END_AT_NULL),
+        where_to_end_(where_to_end),
         is_at_end_(object_->IsNull(isolate_)),
-        seen_proxies_(0) {}
+        seen_proxies_(0) {
+    if (!is_at_end_ && where_to_end_ == END_AT_NON_HIDDEN) {
+      DCHECK(object_->IsJSReceiver());
+      Map* map = JSReceiver::cast(object_)->map();
+      is_at_end_ = !map->has_hidden_prototype();
+    }
+  }
 
-  explicit PrototypeIterator(Handle<Map> receiver_map)
+  explicit PrototypeIterator(Handle<Map> receiver_map,
+                             WhereToEnd where_to_end = END_AT_NULL)
       : isolate_(receiver_map->GetIsolate()),
         object_(NULL),
         handle_(receiver_map->GetPrototypeChainRootMap(isolate_)->prototype(),
                 isolate_),
-        where_to_end_(END_AT_NULL),
+        where_to_end_(where_to_end),
         is_at_end_(handle_->IsNull(isolate_)),
-        seen_proxies_(0) {}
+        seen_proxies_(0) {
+    if (!is_at_end_ && where_to_end_ == END_AT_NON_HIDDEN) {
+      DCHECK(handle_->IsJSReceiver());
+      Map* map = JSReceiver::cast(*handle_)->map();
+      is_at_end_ = !map->has_hidden_prototype();
+    }
+  }
 
   ~PrototypeIterator() {}
 
   bool HasAccess() const {
     // We can only perform access check in the handlified version of the
     // PrototypeIterator.
     DCHECK(!handle_.is_null());
     if (handle_->IsAccessCheckNeeded()) {
       return isolate_->MayAccess(handle(isolate_->context()),
                                  Handle<JSObject>::cast(handle_));
@@ skipping 89 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(PrototypeIterator);
 };
 
 
 }  // namespace internal
 
 }  // namespace v8
 
 #endif  // V8_PROTOTYPE_H_