move enable_localaccount.sh, make pam_offline use it

src/platform/pam_offline/credentials.h

Index: src/platform/pam_offline/credentials.h
diff --git a/src/platform/pam_offline/credentials.h b/src/platform/pam_offline/credentials.h
index d098de87a4479834ed82999f82d591d64312c300..8f0604a582cc16cf63c0cce7069c467f6f615c5c 100644
--- a/src/platform/pam_offline/credentials.h
+++ b/src/platform/pam_offline/credentials.h
@@ -34,6 +34,12 @@ class Credentials {
   //
   virtual void GetPartialUsername(char *name_buffer, int length) const = 0;
 
+#ifdef CHROMEOS_PAM_LOCALACCOUNT
+  // returns true if we're willing to accept these credentials without
+  // talking to Google.
+  virtual bool IsLocalAccount() const = 0;
+#endif
+
   // Returns the obfuscated username, used as the name of the directory
   // containing the user's stateful data (and maybe used for other reasons
   // at some point.)