Implement a proxy for Pepper FileIO.

ppapi/proxy/ppb_file_ref_proxy.h

Index: ppapi/proxy/ppb_file_ref_proxy.h
diff --git a/ppapi/proxy/ppb_file_ref_proxy.h b/ppapi/proxy/ppb_file_ref_proxy.h
index 5f0f947c5e0ac2e7b97ba7916c97a245750eccf5..c0fa23cdda563dcc2886dadaa6d64f23c2c58b71 100644
--- a/ppapi/proxy/ppb_file_ref_proxy.h
+++ b/ppapi/proxy/ppb_file_ref_proxy.h
@@ -31,6 +31,8 @@ class PPB_FileRef_Proxy : public InterfaceProxy {
 
   static PP_Resource CreateProxyResource(PP_Resource file_system,
                                          const char* path);
+  static PP_Resource CreateProxyResource(
+      const PPB_FileRef_CreateInfo& serialized);
 
   // InterfaceProxy implementation.
   virtual bool OnMessageReceived(const IPC::Message& msg);
@@ -60,7 +62,7 @@ class PPB_FileRef_Proxy : public InterfaceProxy {
   static const ApiID kApiID = API_ID_PPB_FILE_REF;
 
  private:
-  // Message handlers.
+  // Plugin -> host message handlers.
   void OnMsgCreate(const HostResource& file_system,
                    const std::string& path,
                    PPB_FileRef_CreateInfo* result);