Return MaybeHandle from Invoke.

src/handles.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 301 matching lines @@
 v8::Handle<v8::Array> GetKeysForNamedInterceptor(Handle<JSReceiver> receiver,
                                                  Handle<JSObject> object);
 v8::Handle<v8::Array> GetKeysForIndexedInterceptor(Handle<JSReceiver> receiver,
                                                    Handle<JSObject> object);
 
 enum KeyCollectionType { LOCAL_ONLY, INCLUDE_PROTOS };
 
 // Computes the enumerable keys for a JSObject. Used for implementing
 // "for (n in object) { }".
 MUST_USE_RESULT MaybeHandle<FixedArray> GetKeysInFixedArrayFor(
-    Handle<JSReceiver> object,
-    KeyCollectionType type);
-MUST_USE_RESULT MaybeHandle<JSArray> GetKeysFor(Handle<JSReceiver> object);
+    Handle<JSReceiver> object, KeyCollectionType type);
 Handle<FixedArray> ReduceFixedArrayTo(Handle<FixedArray> array, int length);
 Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object,
                                        bool cache_result);
 
 Handle<JSGlobalProxy> ReinitializeJSGlobalProxy(
     Handle<JSFunction> constructor,
     Handle<JSGlobalProxy> global);
 
 void AddWeakObjectToCodeDependency(Heap* heap,
                                    Handle<Object> object,
@@ skipping 23 matching lines @@
 
   void Initialize() {
     next = limit = NULL;
     level = 0;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HANDLES_H_