Issue 4962 - Fix the tests.- Fix syntax in chrome/content/elemHideEmulation.js to use ES5Regress…

chrome/content/elemHideEmulation.js

 // We are currently limited to ECMAScript 5 in this file, because it is being
 // used in the browser tests. See https://issues.adblockplus.org/ticket/4796
 
 var propertySelectorRegExp = /\[\-abp\-properties=(["'])([^"']+)\1\]/;
 
 function splitSelector(selector)
 {
   if (selector.indexOf(",") == -1)
     return [selector];
 
@@ skipping 65 matching lines @@
     }
   },
 
   findSelectors: function(stylesheet, selectors, filters)
   {
     // Explicitly ignore third-party stylesheets to ensure consistent behavior
     // between Firefox and Chrome.
     if (!this.isSameOrigin(stylesheet))
       return;
 
-    let rules = stylesheet.cssRules;
+    var rules = stylesheet.cssRules;
     if (!rules)
       return;
 
-    for (let rule of rules)
+    for (var i = 0; i < rules.length; i++)
     {
+      var rule = rules[i];
       if (rule.type != rule.STYLE_RULE)
         continue;
 
-      let style = this.stringifyStyle(rule.style);
-      for (let pattern of this.patterns)
+      var style = this.stringifyStyle(rule.style);
+      this.patterns.forEach(function(pattern)

[Wladimir Palant, 2017/03/08 10:31:50]

Last I checked, calling forEach caused suboptimal performance. Also, I don't see
a point risking more regressions here. It should be best to just revert the
unnecessary changes from https://codereview.adblockplus.org/29372676/.

       {
         if (pattern.regexp.test(style))
         {
-          let subSelectors = splitSelector(rule.selectorText);
-          for (let subSelector of subSelectors)
+          var subSelectors = splitSelector(rule.selectorText);
+          subSelectors.forEach(function(subSelector)
           {
             selectors.push(pattern.prefix + subSelector + pattern.suffix);
             filters.push(pattern.text);
-          }
+          });
         }
-      }
+      });
     }
   },
 
   addSelectors: function(stylesheets)
   {
     var selectors = [];
     var filters = [];
     for (var i = 0; i < stylesheets.length; i++)
       this.findSelectors(stylesheets[i], selectors, filters);
     this.addSelectorsFunc(selectors, filters);
@@ skipping 37 matching lines @@
 
       if (this.patterns.length > 0)
       {
         var document = this.window.document;
         this.addSelectors(document.styleSheets);
         document.addEventListener("load", this.onLoad.bind(this), true);
       }
     }.bind(this));
   }
 };