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

base/bind_internal_win.h

 // This file was GENERATED by command:
 //     pump.py bind_internal_win.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.
 
 // Specializations of RunnableAdapter<> for Windows specific calling
 // conventions.  Please see base/bind_internal.h for more info.
 
 #ifndef BASE_BIND_INTERNAL_WIN_H_
 #define BASE_BIND_INTERNAL_WIN_H_
-#pragma once
 
 // In the x64 architecture in Windows, __fastcall, __stdcall, etc, are all
 // the same as __cdecl which would turn the following specializations into
 // multiple definitions.
 #if !defined(ARCH_CPU_X86_64)
 
 namespace base {
 namespace internal {
 
 template <typename Functor>
@@ skipping 334 matching lines @@
  private:
   R (__fastcall *function_)(A1, A2, A3, A4, A5, A6, A7);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // !defined(ARCH_CPU_X86_64)
 
 #endif  // BASE_BIND_INTERNAL_WIN_H_