Pepper: Move GetSandboxISA() to PPB_NaCl_Private.

ppapi/native_client/src/trusted/plugin/nexe_arch.h

-/*
- * Copyright (c) 2012 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.
- */
-
-// Routines for determining the most appropriate NaCl executable for
-// the current CPU's architecture.
-
-#ifndef NATIVE_CLIENT_SRC_TRUSTED_PLUGIN_NEXE_ARCH_H_
-#define NATIVE_CLIENT_SRC_TRUSTED_PLUGIN_NEXE_ARCH_H_
-
-#include "native_client/src/include/portability.h"
-
-namespace plugin {
-// Returns the kind of SFI sandbox implemented by sel_ldr on this
-// platform.  See the implementation in nexe_arch.cc for possible values.
-//
-// This is a function of the current CPU, OS, browser, installed
-// sel_ldr(s).  It is not sufficient to derive the result only from
-// build-time parameters since, for example, an x86-32 plugin is
-// capable of launching a 64-bit NaCl sandbox if a 64-bit sel_ldr is
-// installed (and indeed, may only be capable of launching a 64-bit
-// sandbox).
-//
-// Note: The platform-sepcific implementations for this are under
-// <platform>/nexe_arch.cc
-const char* GetSandboxISA();
-}  // namespace plugin
-
-#endif  // NATIVE_CLIENT_SRC_TRUSTED_PLUGIN_NEXE_ARCH_H_