Split the PNaCl IRT shim into 3 pieces, and include one piece into IRT.

ppapi/native_client/src/untrusted/pnacl_irt_shim/irt_shim_ppapi.h

+/*
+ * Copyright 2014 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 PPAPI_NATIVE_CLIENT_SRC_UNTRUSTED_PNACL_IRT_SHIM_IRT_SHIM_PPAPI_H_
+#define PPAPI_NATIVE_CLIENT_SRC_UNTRUSTED_PNACL_IRT_SHIM_IRT_SHIM_PPAPI_H_
+
+#include "ppapi/nacl_irt/irt_ppapi.h"
+
+#ifdef PNACL_SHIM_AOT
+
+/* Given a hook for the real irt ppapi start, get a shimmed ppapi_start. */
+extern int (*real_irt_ppapi_start)(const struct PP_StartFunctions *);
+extern int irt_shim_ppapi_start(const struct PP_StartFunctions *funcs);
+
+#else
+
+/*
+ * A private version of the NACL_IRT_PPAPIHOOK_v0_1, which provides
+ * PNaCl with shimmed IRT interfaces.
+ */
+#define NACL_IRT_PPAPIHOOK_PNACL_PRIVATE_v0_1   \
+  "nacl-irt-ppapihook-pnacl-private-0.1"
+extern const struct nacl_irt_ppapihook nacl_irt_ppapihook_pnacl_private;
+
+#endif
+
+#endif