Issue 4000 - cssProperties.js content script should report matching filters

chrome/content/cssProperties.js

 function splitSelector(selector)
 {
   if (selector.indexOf(",") == -1)
     return [selector];
 
   var selectors = [];
   var start = 0;
   var level = 0;
   var sep = "";
 
@@ skipping 53 matching lines @@
     {
       return new URL(stylesheet.href).origin == this.window.location.origin;
     }
     catch (e)
     {
       // Invalid URL, assume that it is first-party.
       return true;
     }
   },
 
-  findSelectors: function(stylesheet, selectors)
+  findSelectors: function(stylesheet, selectors, filters)
   {
     // Explicitly ignore third-party stylesheets to ensure consistent behavior
     // between Firefox and Chrome.
     if (!this.isSameOrigin(stylesheet))
       return;
 
     var rules = stylesheet.cssRules;
     if (!rules)
       return;
 
@@ skipping 10 matching lines @@
         var regexp = pattern.regexp;
 
         if (typeof regexp == "string")
           regexp = pattern.regexp = new RegExp(regexp);
 
         if (regexp.test(style))
         {
           var subSelectors = splitSelector(rule.selectorText);
           for (var k = 0; k < subSelectors.length; k++)
             selectors.push(pattern.prefix + subSelectors[k] + pattern.suffix);
+          filters[pattern.text] = true;
         }
       }
     }
   },
 
   addSelectors: function(stylesheets)
   {
     var selectors = [];
+    var filters = {};
     for (var i = 0; i < stylesheets.length; i++)
-      this.findSelectors(stylesheets[i], selectors);
-    this.addSelectorsFunc(selectors);
+      this.findSelectors(stylesheets[i], selectors, filters);
+    this.addSelectorsFunc(selectors, Object.keys(filters));
   },
 
   onLoad: function(event)
   {
     var stylesheet = event.target.sheet;
     if (stylesheet)
       this.addSelectors([stylesheet]);
   },
 
   load: function(callback)
   {
     this.getFiltersFunc(function(patterns)
     {
       this.patterns = patterns;
       callback();
     }.bind(this));
   },
 
   apply: function()
   {
     if (this.patterns.length > 0)
     {
       var document = this.window.document;
       this.addSelectors(document.styleSheets);
       document.addEventListener("load", this.onLoad.bind(this), true);
     }
   }
 };