Error compiling waitforvsync.cpp

The waitforvsync.cpp throws error when compiling. Following is the error log

target thumb C++: test-waitforvsync <= frameworks/native/services/surfaceflinger/tests/waitforvsync/waitforvsync.cpp
frameworks/native/services/surfaceflinger/tests/waitforvsync/waitforvsync.cpp: In function 'int main(int, char**)':
frameworks/native/services/surfaceflinger/tests/waitforvsync/waitforvsync.cpp:43:17: error: 'close' was not declared in this scope
         close(fd);
                 ^
....
....

make: *** [out/target/product/grouper/obj/EXECUTABLES/test-waitforvsync_intermediates/waitforvsync.o] Error 1

the file is missing #include <unistd.h>

Change-Id: I57728dbde65641cd3138625f9a590f9db8648158
Signed-off-by: Nanik Tolaram <nanikjava@gmail.com>