ES6 Unscopables

src/contexts.cc

Index: src/contexts.cc
diff --git a/src/contexts.cc b/src/contexts.cc
index cb5e852d7d669c07c8d8b950016defff1572f49c..37156d53bc618d1bb835df6b0a61bd0a71022e77 100644
--- a/src/contexts.cc
+++ b/src/contexts.cc
@@ -7,6 +7,7 @@
 #include "src/bootstrapper.h"
 #include "src/debug.h"
 #include "src/scopeinfo.h"
+#include "src/unscopables.h"
 
 namespace v8 {
 namespace internal {
@@ -109,9 +110,14 @@ Handle<Object> Context::Lookup(Handle<String> name,
       if ((flags & FOLLOW_PROTOTYPE_CHAIN) == 0 ||
           object->IsJSContextExtensionObject()) {
         *attributes = JSReceiver::GetOwnPropertyAttributes(object, name);
+      } else if (FLAG_harmony_unscopables && context->IsWithContext()) {
+        bool ok;
+        Handle<JSReceiver> holder;
+        *attributes = UnscopableLookup(isolate, object, name, &holder, &ok);
       } else {
         *attributes = JSReceiver::GetPropertyAttributes(object, name);
       }
+
       if (isolate->has_pending_exception()) return Handle<Object>();
 
       if (*attributes != ABSENT) {