fuchsia: Fix #include for ntohl/htonl

Bug: 808287, 898088
Change-Id: I7aa9dd73aa405e32a46118dfe8474c7849471caf
Reviewed-on: https://chromium-review.googlesource.com/c/1297460Reviewed-by: Nathan Parker <nparker@chromium.org>
Commit-Queue: Scott Graham <scottmg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602417}

components/safe_browsing/db/v4_rice.cc

@@ -13,7 +13,7 @@
 
 #if defined(OS_WIN)
 #include <winsock2.h>
-#elif defined(OS_POSIX)
+#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
 #include <arpa/inet.h>
 #endif