Index: lib/elemHide.js
===================================================================
--- a/lib/elemHide.js
+++ b/lib/elemHide.js
@@ -61,16 +61,48 @@
 
 /**
  * Lookup table, lists of element hiding exceptions by selector
  * @type {Map.<string,Filter>}
  */
 let exceptions = new Map();
 
 /**
+ * Adds a filter to the lookup table of filters by domain.
+ * @param {Filter} filter
+ */
+function addToFiltersByDomain(filter)
+{
+  let domains = filter.domains || defaultDomains;
+  for (let [domain, isIncluded] of domains)
+  {
+    // There's no need to note that a filter is generically disabled.
+    if (!isIncluded && domain == "")
+      continue;
+
+    let filters = filtersByDomain.get(domain);
+    if (!filters)
+      filtersByDomain.set(domain, filters = new Map());
+    filters.set(filter, isIncluded);
+  }
+}
+
+/**
+ * Returns a list of selectors that apply on each website unconditionally.
+ * @returns {string[]}
+ */
+function getUnconditionalSelectors()
+{
+  if (!unconditionalSelectors)
+    unconditionalSelectors = [...filterBySelector.keys()];
+
+  return unconditionalSelectors.slice();
+}
+
+/**
  * Container for element hiding filters
  * @class
  */
 let ElemHide = exports.ElemHide = {
   /**
    * Removes all known filters
    */
   clear()
@@ -79,32 +111,16 @@
                             knownFilters, exceptions])
     {
       collection.clear();
     }
     unconditionalSelectors = null;
     FilterNotifier.emit("elemhideupdate");
   },
 
-  _addToFiltersByDomain(filter)
-  {
-    let domains = filter.domains || defaultDomains;
-    for (let [domain, isIncluded] of domains)
-    {
-      // There's no need to note that a filter is generically disabled.
-      if (!isIncluded && domain == "")
-        continue;
-
-      let filters = filtersByDomain.get(domain);
-      if (!filters)
-        filtersByDomain.set(domain, filters = new Map());
-      filters.set(filter, isIncluded);
-    }
-  },
-
   /**
    * Add a new element hiding filter
    * @param {ElemHideBase} filter
    */
   add(filter)
   {
     if (knownFilters.has(filter))
       return;
@@ -119,31 +135,31 @@
         exceptions.set(selector, [filter]);
 
       // If this is the first exception for a previously unconditionally
       // applied element hiding selector we need to take care to update the
       // lookups.
       let unconditionalFilterForSelector = filterBySelector.get(selector);
       if (unconditionalFilterForSelector)
       {
-        this._addToFiltersByDomain(unconditionalFilterForSelector);
+        addToFiltersByDomain(unconditionalFilterForSelector);
         filterBySelector.delete(selector);
         unconditionalSelectors = null;
       }
     }
     else if (!(filter.domains || exceptions.has(filter.selector)))
     {
       // The new filter's selector is unconditionally applied to all domains
       filterBySelector.set(filter.selector, filter);
       unconditionalSelectors = null;
     }
     else
     {
       // The new filter's selector only applies to some domains
-      this._addToFiltersByDomain(filter);
+      addToFiltersByDomain(filter);
     }
 
     knownFilters.add(filter);
     FilterNotifier.emit("elemhideupdate");
   },
 
   /**
    * Removes an element hiding filter
@@ -202,27 +218,16 @@
       if (list[i].isActiveOnDomain(docDomain))
         return list[i];
     }
 
     return null;
   },
 
   /**
-   * Returns a list of selectors that apply on each website unconditionally.
-   * @returns {string[]}
-   */
-  getUnconditionalSelectors()
-  {
-    if (!unconditionalSelectors)
-      unconditionalSelectors = [...filterBySelector.keys()];
-    return unconditionalSelectors.slice();
-  },
-
-  /**
    * Constant used by getSelectorsForDomain to return all selectors applying to
    * a particular hostname.
    * @type {number}
    * @const
    */
   ALL_MATCHING: 0,
 
   /**
@@ -251,17 +256,17 @@
    * @returns {string[]}
    *   List of selectors.
    */
   getSelectorsForDomain(domain, criteria = ElemHide.ALL_MATCHING)
   {
     let selectors = [];
 
     if (criteria < ElemHide.NO_UNCONDITIONAL)
-      selectors = this.getUnconditionalSelectors();
+      selectors = getUnconditionalSelectors();
 
     let specificOnly = (criteria >= ElemHide.SPECIFIC_ONLY);
     let excluded = new Set();
     let currentDomain = domain ? domain.toUpperCase() : "";
 
     // This code is a performance hot-spot, which is why we've made certain
     // micro-optimisations. Please be careful before making changes.
     while (true)