Add NaCl proxy for pepper gamepad

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

+# 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.
+
+# RPC methods used to implement PPB_Gamepad interface.
+# See ppapi/c/dev/ppb_gamepad_dev.h for interface details.
+{
+ 'name': 'PpbGamepadRpc',
+ 'rpcs': [
+          {'name': 'PPB_Gamepad_SampleGamepads',
+           'inputs': [['instance', 'PP_Instance']],
+           'outputs': [['data', 'char[]']]            # PP_GamepadsData_Dev
+          },
+         ]
+}