Noissue - Delete element hiding domain entry once all filters removed

lib/elemHide.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 177 matching lines @@
       unconditionalSelectors = null;
     }
     // Conditionally applied element hiding filters
     else
     {
       let domains = filter.domains || defaultDomains;
       for (let domain of domains.keys())
       {
         let filters = filtersByDomain.get(domain);
         if (filters)
+        {
           filters.delete(filter);
+
+          if (filters.size == 0)
+            filtersByDomain.delete(domain);
+        }
       }
     }
 
     knownFilters.delete(filter);
     FilterNotifier.emit("elemhideupdate");
   },
 
   /**
    * Checks whether an exception rule is registered for a selector on a
    * particular domain.
@@ skipping 64 matching lines @@
       let nextDot = currentDomain.indexOf(".");
       currentDomain = nextDot == -1 ? "" : currentDomain.substr(nextDot + 1);
     }
 
     if (!specificOnly)
       selectors = getUnconditionalSelectors().concat(selectors);
 
     return selectors;
   }
 };