Callback: De-inline CallbackBase, and move to callback_helpers -> callback_internal.h

base/bind.h.pump

 $$ This is a pump file for generating file templates.  Pump is a python
 $$ script that is part of the Google Test suite of utilities.  Description
 $$ can be found here:
 $$
 $$ http://code.google.com/p/googletest/wiki/PumpManual
 $$
 
 $var MAX_ARITY = 6
 
 // Copyright (c) 2011 The Chromium 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 BASE_BIND_H_
 #define BASE_BIND_H_
 #pragma once
 
 #include "base/bind_internal.h"
-#include "base/callback_helpers.h"
+#include "base/callback_internal.h"
 
 // See base/callback.h for how to use these functions.
 //
 // IMPLEMENTATION NOTE
 // Though Bind()'s result is meant to be stored in a Callback<> type, it
 // cannot actually return the exact type without requiring a large amount
 // of extra template specializations. The problem is that in order to
 // discern the correct specialization of Callback<>, Bind would need to
 // unwrap the function signature to determine the signature's arity, and
 // whether or not it is a method.
@@ skipping 32 matching lines @@
           f, $for BOUND_ARG , [[p$(BOUND_ARG)]]));
 }
 
 ]]
 
 ]]  $$ for BOUND
 
 }  // namespace base
 
 #endif  // BASE_BIND_H_