Fix up some types in the API.

ppapi/lib/gl/gles2/gl2ext_ppapi.c

 // Copyright (c) 2010 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.
 
 #include "ppapi/lib/gl/gles2/gl2ext_ppapi.h"
 
+#include <stddef.h>
+
 #ifndef GL_FALSE
 #define GL_FALSE 0
 #endif  // GL_FALSE
 
 #ifndef GL_TRUE
 #define GL_TRUE 1
 #endif  // GL_TRUE
 
 #if defined(__GNUC__) && !defined(__APPLE__)
 #define PP_TLS __thread
@@ skipping 29 matching lines @@
 }
 
 PP_Resource GL_APIENTRY glGetCurrentContextPPAPI() {
   return g_current_context;
 }
 
 const struct PPB_OpenGLES2_Dev* GL_APIENTRY glGetInterfacePPAPI() {
   return g_gles2_interface;
 }