Make PPAPI headers compilable with -Wstrict-prototypes

ppapi/c/ppb_image_data.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_image_data.idl modified Wed Oct 31 10:35:03 2012. */
+/* From ppb_image_data.idl modified Tue Nov 13 08:48:25 2012. */
 
 #ifndef PPAPI_C_PPB_IMAGE_DATA_H_
 #define PPAPI_C_PPB_IMAGE_DATA_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_size.h"
 #include "ppapi/c/pp_stdint.h"
@@ skipping 90 matching lines @@
  */
 struct PPB_ImageData_1_0 {
   /**
    * GetNativeImageDataFormat() returns the browser's preferred format for
    * image data. The browser uses this format internally for painting. Other
    * formats may require internal conversions to paint or may have additional
    * restrictions depending on the function.
    *
    * @return A <code>PP_ImageDataFormat</code> containing the preferred format.
    */
-  PP_ImageDataFormat (*GetNativeImageDataFormat)();
+  PP_ImageDataFormat (*GetNativeImageDataFormat)(void);
   /**
    * IsImageDataFormatSupported() determines if the given image data format is
    * supported by the browser. Note: <code>PP_IMAGEDATAFORMAT_BGRA_PREMUL</code>
    * and <code>PP_IMAGEDATAFORMAT_RGBA_PREMUL</code> formats are always
    * supported. Other image formats do not make this guarantee, and should be
    * checked first with IsImageDataFormatSupported() before using.
    *
    * @param[in] format The image data format.
    *
    * @return A <code>PP_Bool</code> with <code>PP_TRUE</code> if the given
@@ skipping 71 matching lines @@
   void (*Unmap)(PP_Resource image_data);
 };
 
 typedef struct PPB_ImageData_1_0 PPB_ImageData;
 /**
  * @}
  */
 
 #endif  /* PPAPI_C_PPB_IMAGE_DATA_H_ */