patchpanel: Move wwan masquerade from script

BUG=b:156200410
TEST=units

Change-Id: I7397b98c1cbed74eea0debaff1ad2c918e7be318
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform2/+/2214844
Tested-by: Garrick Evans <garrick@chromium.org>
Commit-Queue: Garrick Evans <garrick@chromium.org>
Reviewed-by: Hugo Benichi <hugobenichi@google.com>
diff --git a/patchpanel/datapath.h b/patchpanel/datapath.h
index 3dc5dbd..dcdcf04 100644
--- a/patchpanel/datapath.h
+++ b/patchpanel/datapath.h
@@ -122,6 +122,9 @@
   virtual bool AddSNATMarkRules();
   virtual void RemoveSNATMarkRules();
 
+  virtual bool AddInterfaceSNAT(const std::string& ifname);
+  virtual void RemoveInterfaceSNAT(const std::string& ifname);
+
   // Create (or delete) a mangle PREROUTING rule for marking IPv4 traffic
   // outgoing of |ifname| with the SNAT fwmark value 0x1.
   // TODO(hugobenichi) Refer to RoutingService to obtain the fwmark value and