Add missing includes.

Change-Id: I81e1b647f6909f0c85a67094e4fbc1198bf65516
Exempt-From-Owner-Approval: trivial cleanup
Test: mma
Bug: None
diff --git a/gralloc/gralloc_module.cpp b/gralloc/gralloc_module.cpp
index 70d2c69..73e5c17 100644
--- a/gralloc/gralloc_module.cpp
+++ b/gralloc/gralloc_module.cpp
@@ -18,6 +18,7 @@
 
 #include <errno.h>
 #include <pthread.h>
+#include <string.h>
 
 #include <cutils/log.h>
 #include <cutils/atomic.h>