[Sync] Ensure referrer is recorded regardless of policy conversion

components/sessions/core/serialized_navigation_driver.h

Index: components/sessions/core/serialized_navigation_driver.h
diff --git a/components/sessions/core/serialized_navigation_driver.h b/components/sessions/core/serialized_navigation_driver.h
index 74bbfefe1cbe9fbc3d1b323a2fa0c23d9fcfe132..2a9f74f8230c4c50dbdb1843dbcfce62b86ae9d6 100644
--- a/components/sessions/core/serialized_navigation_driver.h
+++ b/components/sessions/core/serialized_navigation_driver.h
@@ -24,18 +24,6 @@ class SESSIONS_EXPORT SerializedNavigationDriver {
   // Returns the default referrer policy.
   virtual int GetDefaultReferrerPolicy() const = 0;
 
-  // Maps current referrer policies to old values to work around
-  // crbug.com/450589. Returns false if the referrer should be stripped.
-  virtual bool MapReferrerPolicyToOldValues(
-      int referrer_policy,
-      int* mapped_referrer_policy) const = 0;
-
-  // Sanitizes a referrer policy that might either be in the old or the new
-  // format. Returns false if the referrer should be stripped.
-  virtual bool MapReferrerPolicyToNewValues(
-      int referrer_policy,
-      int* mapped_referrer_policy) const = 0;
-
   // Returns a sanitized version of the given |navigation|'s encoded_page_state
   // suitable for writing to disk.
   virtual std::string GetSanitizedPageStateForPickle(