Make PPAPI headers compilable with -Wstrict-prototypes

ppapi/c/ppb_message_loop.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.
  */
 
-/* From ppb_message_loop.idl modified Mon Nov 12 13:33:16 2012. */
+/* From ppb_message_loop.idl modified Tue Nov 20 08:49:26 2012. */
 
 #ifndef PPAPI_C_PPB_MESSAGE_LOOP_H_
 #define PPAPI_C_PPB_MESSAGE_LOOP_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_stdint.h"
@@ skipping 131 matching lines @@
    *
    * This may be called from any thread. After your thread starts but before
    * issuing any other PPAPI calls on it, you must associate it with a message
    * loop by calling AttachToCurrentThread.
    */
   PP_Resource (*Create)(PP_Instance instance);
   /**
    * Returns a resource identifying the message loop for the main thread. The
    * main thread always has a message loop created by the system.
    */
-  PP_Resource (*GetForMainThread)();
+  PP_Resource (*GetForMainThread)(void);
   /**
    * Returns a reference to the PPB_MessageLoop object attached to the current
    * thread. If there is no attached message loop, the return value will be 0.
    */
-  PP_Resource (*GetCurrent)();
+  PP_Resource (*GetCurrent)(void);
   /**
    * Sets the given message loop resource as being the associated message loop
    * for the currently running thread.
    *
    * You must call this function exactly once on a thread before making any
    * PPAPI calls. A message loop can only be attached to one thread, and the
    * message loop can not be changed later. The message loop will be attached
    * as long as the thread is running or until you quit with should_destroy
    * set to PP_TRUE.
    *
@@ skipping 106 matching lines @@
   int32_t (*PostQuit)(PP_Resource message_loop, PP_Bool should_destroy);
 };
 
 typedef struct PPB_MessageLoop_1_0 PPB_MessageLoop;
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_PPB_MESSAGE_LOOP_H_ */