Optimize web request listener-related logic

core/state-manager.js

@@ -137,25 +137,11 @@ stateManager.removeDomainFromWhitelist = function (domain) {
 
 stateManager._createTab = function (tab) {
 
-    let tabIdentifier, requestFilters;
-
-    tabIdentifier = tab.id;
+    let tabIdentifier = tab.id;
 
     stateManager.tabs[tabIdentifier] = {
         'injections': {}
     };
-
-    requestFilters = {
-        'tabId': tabIdentifier,
-        'urls': stateManager.validHosts
-    };
-
-    chrome.webRequest.onBeforeRequest.addListener(function (requestDetails) {
-
-        let tab = stateManager.tabs[tabIdentifier].details || {};
-        return interceptor.handleRequest(requestDetails, tabIdentifier, tab);
-
-    }, requestFilters, [WebRequest.BLOCKING]);
 };
 
 stateManager._removeTab = function (tabIdentifier) {
@@ -302,6 +288,17 @@ for (let mapping in mappings) {
     stateManager.validHosts.push(supportedHost);
 }
 
+stateManager.requestFilters = {
+    'urls': stateManager.validHosts
+};
+
+chrome.webRequest.onBeforeRequest.addListener(function (requestDetails) {
+
+    let tab = stateManager.tabs[requestDetails.tabId].details || {};
+    return interceptor.handleRequest(requestDetails, requestDetails.tabId, tab);
+
+}, stateManager.requestFilters, [WebRequest.BLOCKING]);
+
 chrome.tabs.query({}, function (tabs) {
     tabs.forEach(stateManager._createTab);
 });