PPAPI: Make generator support "no_interface_string"

ppapi/generators/test_cgen/interface.h

 /*
  * Copyright (c) 2011 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.
  */
 
 /* From test_cgen/interface.idl modified Wed Nov 21 14:22:50 2012. */
 
 #ifndef PPAPI_C_TEST_CGEN_INTERFACE_H_
 #define PPAPI_C_TEST_CGEN_INTERFACE_H_
@@ skipping 48 matching lines @@
 };
 
 typedef struct ifaceFoo_1_0 ifaceFoo;
 
 struct ifaceBar_1_0 {
   int8_t (*testIface)(const struct ifaceFoo_1_0* foo, int32_t y);
   struct ifaceFoo_1_0* (*createIface)(const char* name);
 };
 
 typedef struct ifaceBar_1_0 ifaceBar;
+
+struct ifaceNoString_1_0 {
+  void (*mem)(void);
+};
+
+typedef struct ifaceNoString_1_0 ifaceNoString;
 /**
  * @}
  */
 
 /**
  * @addtogroup Structs
  * @{
  */
 struct struct2 {
   struct ifaceBar_1_0* bar;
 };
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_TEST_CGEN_INTERFACE_H_ */