Add NaCl proxy for pepper gamepad

ppapi/native_client/src/shared/ppapi_proxy/build.scons

 # -*- python -*-
 # 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.
 
 import os
 
 Import('env')
 
 # To get generated include files.
@@ skipping 28 matching lines @@
                  'browser_ppb_audio_rpc_server.cc',
                  'browser_ppb_audio_config_rpc_server.cc',
                  'browser_ppb_core_rpc_server.cc',
                  'browser_ppb_cursor_control_rpc_server.cc',
                  'browser_ppb_file_io_rpc_server.cc',
                  'browser_ppb_file_ref_rpc_server.cc',
                  'browser_ppb_file_system_rpc_server.cc',
                  'browser_ppb_find_rpc_server.cc',
                  'browser_ppb_font_rpc_server.cc',
                  'browser_ppb_fullscreen_rpc_server.cc',
+                 'browser_ppb_gamepad_rpc_server.cc',
                  'browser_ppb_graphics_2d_rpc_server.cc',
                  'browser_ppb_graphics_3d_rpc_server.cc',
                  'browser_ppb_image_data_rpc_server.cc',
                  'browser_ppb_input_event_rpc_server.cc',
                  'browser_ppb_instance_rpc_server.cc',
                  'browser_ppb_messaging_rpc_server.cc',
                  'browser_ppb_mouse_lock_rpc_server.cc',
                  'browser_ppb_pdf_rpc_server.cc',
                  'browser_ppb_rpc_server.cc',
                  'browser_ppb_scrollbar_rpc_server.cc',
@@ skipping 27 matching lines @@
                  common_obj,])
 
 
 # The PPAPI RPCs are specified abstractly via .srpc files.
 # Add new .srpc files to the appropriate list in run_srpcgen.py
 # and then run that script.
 # The .cc files are written to ./ and .h files to ./{un,}trusted/srpcgen/.
 # The generated files must be committed when changes are made to .srpc files.
 #
 # run_srpcgen.py --diff_mode verifies that these files are not out of date.