Bug 1189871 - Add event to add/remove permissions for Graphene. r=fabrice

b2g/chrome/content/shell.js

@@ -738,6 +738,14 @@ Services.obs.addObserver(function(subject, topic, data) {
   shell.sendCustomEvent('mozmemorypressure');
 }, 'memory-pressure', false);
 
+let permissionMap = new Map([
+  ['unknown', Services.perms.UNKNOWN_ACTION],
+  ['allow', Services.perms.ALLOW_ACTION],
+  ['deny', Services.perms.DENY_ACTION],
+  ['prompt', Services.perms.PROMPT_ACTION],
+]);
+let permissionMapRev = new Map(Array.from(permissionMap.entries()).reverse());
+
 var CustomEventManager = {
   init: function custevt_init() {
     window.addEventListener("ContentStart", (function(evt) {
@@ -783,6 +791,22 @@ var CustomEventManager = {
         Services.obs.notifyObservers({ wrappedJSObject: shell.contentBrowser },
                                      'ask-children-to-execute-copypaste-command', detail.cmd);
         break;
+      case 'add-permission':
+        Services.perms.add(Services.io.newURI(detail.uri, null, null),
+                           detail.permissionType, permissionMap.get(detail.permission));
+        break;
+      case 'remove-permission':
+        Services.perms.remove(Services.io.newURI(detail.uri, null, null),
+                              detail.permissionType);
+        break;
+      case 'test-permission':
+        let result = Services.perms.testExactPermission(
+          Services.io.newURI(detail.uri, null, null), detail.permissionType);
+        // Not equal check here because we want to prevent default only if it's not set
+        if (result !== permissionMapRev.get(detail.permission)) {
+          evt.preventDefault();
+        }
+        break;
     }
   }
 }