Relocating files in the nacl repo that belong in chrome.

ppapi/native_client/src/untrusted/nacl_ppapi_util/ppapi_srpc_main.c

+/*
+ * 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/shared/srpc/nacl_srpc.h"
+#include "native_client/src/untrusted/nacl_ppapi_util/ppapi_srpc_main.h"
+
+/*
+ * Here be dragons.  Beware.
+ *
+ * We need to provide a main so that when this code is compiled with
+ * irt=1, we can invoke NaClSrpcModuleInit.  This is not needed when
+ * we compile with irt=0 because the PpapiPluginMain uses SRPC and
+ * will invoke NaClSrpcModuleInit.  However, with irt=1, there are two
+ * copies of the SRPC (and platform, and ...) libraries: the
+ * PpapiPluginMain code uses a copy of SRPC in the IRT, and the user
+ * code -- that's us -- has another copy.  The two copies have
+ * separate allocators, globals, etc because of the IRT separation, so
+ * that the NaClSrpcModuleInit that is invoked in the IRT will not
+ * initialize the data structures used by the copy in the user code.
+ *
+ * The weak reference to the function __nacl_register_thread_creator
+ * is an IRT implementation-dependent hack.  Here's how it works.  In
+ * irt_stub, there is a definition for __nacl_register_thread_creator,
+ * so if this code is compiled and linked with irt=1, the weak symbol
+ * will be overridden with a real function, and the tests inside of
+ * main will succeed.  If this code is compiled and linked with irt=0,
+ * however, we will not link against irt_stub (-lppapi which is a
+ * linker script which causes libppapi_stub.a to get included, which
+ * includes the code from the src/untrusted/irt_stub directory), and
+ * so the __nacl_register_thread_creator weak symbol will have the
+ * value zero.  Voila, we call NaClSrpcModuleInit in the main function
+ * below if the scons command invocation had irt=1 set, and we will
+ * leave it to PpapiPluginMain to invoke NaClSrpcModuleInit when the
+ * scons invocation had irt=0 set.
+ *
+ * Yes, this could be conditionally linked in via scons magic by
+ * testing the irt bit, avoiding the weak attribute magic.
+ */
+
+struct nacl_irt_ppapihook;
+
+void __nacl_register_thread_creator(const struct nacl_irt_ppapihook *)
+    __attribute__((weak));
+
+int main(void) {
+  int rv;
+
+  if (__nacl_register_thread_creator) {
+    if (!NaClSrpcModuleInit()) {
+      return 1;
+    }
+  }
+
+  rv = PpapiPluginMain();
+
+  if (__nacl_register_thread_creator) {
+    NaClSrpcModuleFini();
+  }
+
+  return rv;
+}