support elemhide filter option

src/js/messaging.js

@@ -402,7 +402,7 @@ var onMessage = function(details, sender, callback) {
 
     switch ( details.what ) {
         case 'retrieveGenericCosmeticSelectors':
-            if ( pageStore && pageStore.getNetFilteringSwitch() ) {
+            if ( pageStore && pageStore.getCosmeticFilteringSwitch() ) {
                 response = µb.cosmeticFilteringEngine.retrieveGenericSelectors(details);
             }
             break;

src/js/pagestore.js

@@ -492,6 +492,12 @@ PageStore.prototype.init = function(tabId, pageURL) {
     this.skipLocalMirroring = false;
     this.netFilteringCache = NetFilteringResultCache.factory();
 
+    // Support `elemhide` filter option. Called at this point so the required
+    // context is all setup at this point.
+    this.skipCosmeticFiltering = µb.staticNetFilteringEngine
+                                   .matchStringExactType(this, pageURL, 'cosmetic-filtering')
+                                   .charAt(1) === 'b';
+
     // Preserve old buffer if there is one already, it may be in use, and
     // overwritting it would required another read to restart it.
     if ( this.logBuffer instanceof LogBuffer === false ) {
@@ -596,6 +602,13 @@ PageStore.prototype.getNetFilteringSwitch = function() {
 
 /******************************************************************************/
 
+PageStore.prototype.getCosmeticFilteringSwitch = function() {
+    return this.getNetFilteringSwitch() === false ||
+           this.skipCosmeticFiltering == false;
+};
+
+/******************************************************************************/
+
 PageStore.prototype.filterRequest = function(context) {
     if ( this.getNetFilteringSwitch() === false ) {
         this.cacheResult(context, '');

src/js/static-net-filtering.js

@@ -64,6 +64,7 @@ var typeNameToTypeValue = {
     'xmlhttprequest':  6 << 4,
          'sub_frame':  7 << 4,
              'other':  8 << 4,
+'cosmetic-filtering': 13 << 4,
      'inline-script': 14 << 4,
              'popup': 15 << 4
 };
@@ -1245,6 +1246,11 @@ FilterParser.prototype.parse = function(s) {
             this.parseOptParty(not);
             continue;
         }
+        if ( opt === 'elemhide' && this.action === AllowAction ) {
+            this.types.push(typeNameToTypeValue['cosmetic-filtering']);
+            this.action = BlockAction;
+            continue;
+        }
         if ( this.toNormalizedType.hasOwnProperty(opt) ) {
             this.parseOptType(opt, not);
             continue;