Remove #pragma once. Just from base/ for now.

base/bind.h

 // This file was GENERATED by command:
 //     pump.py bind.h.pump
 // DO NOT EDIT BY HAND!!!
 
 
 // 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_internal.h"
 
 // See base/callback.h for how to use these functions. If reading the
 // implementation, before proceeding further, you should read the top
 // comment of base/bind_internal.h for a definition of common terms and
 // concepts.
 //
 // IMPLEMENTATION NOTE
@@ skipping 475 matching lines @@
 
 
   return Callback<typename BindState::UnboundRunType>(
       new BindState(internal::MakeRunnable(functor), p1, p2, p3, p4, p5, p6,
           p7));
 }
 
 }  // namespace base
 
 #endif  // BASE_BIND_H_