NaCl: Remove getpid() calls from the PPAPI proxy

ppapi/native_client/src/shared/ppapi_proxy/ppp.srpc

 # 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.
 
 # This file declares the RPC methods used to implement PPAPI calls from
 # the browser to the plugin.  It implements the interface in ppapi/c/ppp.h.
 {
  'name': 'PppRpc',
  'rpcs': [
           # PPP_Initialize is called once to initialize the plugin.
           # It is effectively a class initializer for the plugin type.
           {'name': 'PPP_InitializeModule',
-           'inputs': [['pid', 'int32_t'],
-                      ['module', 'PP_Module'],
+           'inputs': [['module', 'PP_Module'],
                       ['upcall_channel_desc', 'handle'],
                       ['service_description', 'string'],
                      ],
-           'outputs': [['nacl_pid', 'int32_t'],
-                       ['success', 'int32_t'],
+           'outputs': [['success', 'int32_t'],
                       ]
           },
           # PPP_ShutdownModule stops the plugin.
           {'name': 'PPP_ShutdownModule',
            'inputs': [],
            'outputs': []
           },
           # PPP_GetInterface checks whether the plugin exports a specified
           # interface name.
           {'name': 'PPP_GetInterface',
            'inputs': [['interface_name', 'string'],
                      ],
            'outputs': [['exports_interface_name', 'int32_t'],
                       ]
           },
          ]
 }