Cloning a bunch of stuff from the native_client repository at r6528

ppapi/native_client/src/shared/ppapi_proxy/plugin_main.cc

Index: ppapi/native_client/src/shared/ppapi_proxy/plugin_main.cc
===================================================================
--- ppapi/native_client/src/shared/ppapi_proxy/plugin_main.cc	(revision 0)
+++ ppapi/native_client/src/shared/ppapi_proxy/plugin_main.cc	(revision 0)
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2010 The Native Client 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/ppapi_proxy/ppruntime.h"
+
+// PPAPI plugins are actually "hosted" by ppruntime.  This is because the
+// library needs to start an SRPC loop to dispatch to the stubs.
+//
+// This definition is weak to allow customers to override it when
+// initialization is needed before the main PPAPI processing happens.
+
+int __attribute__ ((weak)) main(int argc, char* argv[]) {
+  return PpapiPluginMain();
+}