Initialize extension storage for domains to manipulate DOM (#1)

core/constants.js

@@ -69,7 +69,8 @@ const Setting = {
     'LAST_MAPPING_UPDATE': 'lastMappingUpdate',
     'WHITELISTED_DOMAINS': 'whitelistedDomains',
     'XHR_TEST_DOMAIN': 'xhrTestDomain',
-    'LOGGING': 'enableLogging'
+    'LOGGING': 'enableLogging',
+    'DOMAINS_MANIPULATE_DOM': 'domainsManipulateDOM'
 };
 
 const WebRequest = {

core/main.js

@@ -34,7 +34,8 @@ main._initializeSettings = function () {
         [Setting.HIDE_RELEASE_NOTES]: false,
         [Setting.STRIP_METADATA]: true,
         [Setting.WHITELISTED_DOMAINS]: {},
-        [Setting.LOGGING]: false
+        [Setting.LOGGING]: false,
+        [Setting.DOMAINS_MANIPULATE_DOM]: {}
     };
 
     chrome.storage.local.get(settingDefaults, function (items) {