ES6 Unscopables

src/contexts.cc

Index: src/contexts.cc
diff --git a/src/contexts.cc b/src/contexts.cc
index 60cf93f8d35dce48439c70b035d27cc24b2fed95..58ec94f6730e1bcd866d4eb0d698b5e079b711ce 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 {
@@ -110,9 +111,13 @@ Handle<Object> Context::Lookup(Handle<String> name,
       if ((flags & FOLLOW_PROTOTYPE_CHAIN) == 0 ||
           object->IsJSContextExtensionObject()) {
         maybe = JSReceiver::GetOwnPropertyAttributes(object, name);
+      } else if (FLAG_harmony_unscopables && context->IsWithContext()) {
+        LookupIterator it(object, name);
+        maybe = UnscopableLookup(&it);
       } else {
         maybe = JSReceiver::GetPropertyAttributes(object, name);
       }
+
       if (!maybe.has_value) return Handle<Object>();
       ASSERT(!isolate->has_pending_exception());
       *attributes = maybe.value;