[EasyUnlock] Force user to enter their password after 20 hours.

components/proximity_auth/proximity_auth_pref_manager.h

Index: components/proximity_auth/proximity_auth_pref_manager.h
diff --git a/components/proximity_auth/proximity_auth_pref_manager.h b/components/proximity_auth/proximity_auth_pref_manager.h
index 095f54c1e4c2414e553f329aa6f2be0a62b527d8..9f74191417fc2f6efe8823ad2e81f4e26085ead1 100644
--- a/components/proximity_auth/proximity_auth_pref_manager.h
+++ b/components/proximity_auth/proximity_auth_pref_manager.h
@@ -59,6 +59,12 @@ class ProximityAuthPrefManager {
   virtual std::string GetDeviceAddress(const std::string& public_key) const;
   virtual std::vector<std::string> GetPublicKeys() const;
 
+  // Setter and getter for the timestamp of the last password entry. This
+  // preference is used to enforce reauthing with the password after a given
+  // time period has elapsed.
+  virtual void SetLastPasswordEntryTimestampMs(int64_t timestamp_ms);
+  virtual int64_t GetLastPasswordEntryTimestampMs() const;
+
  private:
   const base::DictionaryValue* GetRemoteBleDevices() const;