Pepper: Move GetSandboxISA() to PPB_NaCl_Private.

ppapi/native_client/src/trusted/plugin/arch_x86/sandbox_isa.cc

-// 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.
-
-#include "native_client/src/trusted/platform_qualify/nacl_os_qualify.h"
-#include "ppapi/native_client/src/trusted/plugin/nexe_arch.h"
-
-// The list of supported ISA strings for x86.  See issue:
-//   http://code.google.com/p/nativeclient/issues/detail?id=1040 for more
-// information.  Note that these string are to be case-insensitive compared.
-const char kNexeArchX86_64[] = "x86-64";
-#if !((NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86 && NACL_BUILD_SUBARCH == 64) && \
-    (defined(NACL_LINUX) || defined(NACL_OSX)))
-const char kNexeArchX86_32[] = "x86-32";
-#endif
-
-namespace plugin {
-const char* GetSandboxISA() {
-#if (NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86 && NACL_BUILD_SUBARCH == 64) && \
-    (defined(NACL_LINUX) || defined(NACL_OSX))
-  return kNexeArchX86_64;  // 64-bit Linux or Mac.
-#else
-  return NaClOsIs64BitWindows() == 1
-      ? kNexeArchX86_64  // 64-bit Windows (Chrome, Firefox)
-      : kNexeArchX86_32;  // everything else.
-#endif
-}
-}  // namespace plugin