adb/base: allow use of unique_fd inside adb.

adb implements its own file descriptor emulation layer on Windows,
which requires the use of adb_close instead of close throughout the
codebase. Add a template argument to unique_fd that allows for this.

Bug: http://b/28347842
Change-Id: I6397261f4973d49f2f8e04257bf67b348585bb63
diff --git a/adb/sysdeps.h b/adb/sysdeps.h
index 3586da8..639f8eb 100644
--- a/adb/sysdeps.h
+++ b/adb/sysdeps.h
@@ -29,8 +29,9 @@
 #include <string>
 #include <vector>
 
-// Include this before open/unlink are defined as macros below.
+// Include this before open/close/unlink are defined as macros below.
 #include <android-base/errors.h>
+#include <android-base/unique_fd.h>
 #include <android-base/utf8.h>
 
 /*