Check for _WIN32 instead of WIN32.
_WIN32 is predefined for the Windows platform in MSVC, whereas WIN32 is not, and WIN32 is also not defined in the makefiles.
Change-Id: I8b58e42d891608dbe1e1313dc9629c2be588d9ec
diff --git a/vp8/decoder/threading.c b/vp8/decoder/threading.c
index 561922d..491e2ce 100644
--- a/vp8/decoder/threading.c
+++ b/vp8/decoder/threading.c
@@ -10,7 +10,7 @@
#include "vpx_config.h"
#include "vp8_rtcd.h"
-#if !defined(WIN32) && CONFIG_OS_SUPPORT == 1
+#if !defined(_WIN32) && CONFIG_OS_SUPPORT == 1
#include <unistd.h>
#endif
#include "onyxd_int.h"