am 56f8c6c4: Merge "Error compiling waitforvsync.cpp"

* commit '56f8c6c42dab4c3636edb62162088e5d765fa956':
  Error compiling waitforvsync.cpp
diff --git a/services/surfaceflinger/tests/waitforvsync/waitforvsync.cpp b/services/surfaceflinger/tests/waitforvsync/waitforvsync.cpp
index 279b88b..b88b04a 100644
--- a/services/surfaceflinger/tests/waitforvsync/waitforvsync.cpp
+++ b/services/surfaceflinger/tests/waitforvsync/waitforvsync.cpp
@@ -23,6 +23,7 @@
 #include <errno.h>
 #include <string.h>
 #include <stdio.h>
+#include <unistd.h>
 
 #ifndef FBIO_WAITFORVSYNC
 #define FBIO_WAITFORVSYNC   _IOW('F', 0x20, __u32)