Refactor the way singleton-style resources are exposed via PPB_Instance

ppapi/shared_impl/resource.h

 // 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.
 
 #ifndef PPAPI_SHARED_IMPL_RESOURCE_H_
 #define PPAPI_SHARED_IMPL_RESOURCE_H_
 
 #include <stddef.h>  // For NULL.
 
 #include <string>
@@ skipping 22 matching lines @@
   F(PPB_FileIO_API) \
   F(PPB_FileRef_API) \
   F(PPB_FileSystem_API) \
   F(PPB_Find_API) \
   F(PPB_Flash_Clipboard_API) \
   F(PPB_Flash_DeviceID_API) \
   F(PPB_Flash_FontFile_API) \
   F(PPB_Flash_Functions_API) \
   F(PPB_Flash_Menu_API) \
   F(PPB_Flash_MessageLoop_API) \
+  F(PPB_Gamepad_API) \
   F(PPB_Graphics2D_API) \
   F(PPB_Graphics3D_API) \
   F(PPB_HostResolver_Private_API) \
   F(PPB_ImageData_API) \
   F(PPB_InputEvent_API) \
   F(PPB_LayerCompositor_API) \
   F(PPB_MessageLoop_API) \
   F(PPB_NetworkList_Private_API) \
   F(PPB_NetworkMonitor_Private_API) \
   F(PPB_PDFFont_API) \
@@ skipping 165 matching lines @@
 #define DEFINE_RESOURCE_CAST(RESOURCE) \
   template<> inline thunk::RESOURCE* Resource::GetAs() { \
     return As##RESOURCE(); \
   }
 FOR_ALL_PPAPI_RESOURCE_APIS(DEFINE_RESOURCE_CAST)
 #undef DEFINE_RESOURCE_CAST
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_RESOURCE_H_