Bug 1297028 Expose Addon.canUninstall flag to content r=bz,rhelmer

MozReview-Commit-ID: Ec6QPj9h9k7

--HG--
extra : rebase_source : 747cb4ce54d5e8d0cc7bc2cc3654471b3b07bfcb

dom/webidl/AddonManager.webidl

@@ -24,6 +24,8 @@ interface Addon {
   readonly attribute boolean isEnabled;
   // If the add-on is currently active in the browser.
   readonly attribute boolean isActive;
+  // If the add-on may be uninstalled
+  readonly attribute boolean canUninstall;
 
   Promise<boolean> uninstall();
   Promise<void> setEnabled(boolean value);

toolkit/mozapps/extensions/AddonManager.jsm

@@ -335,6 +335,7 @@ function webAPIForAddon(addon) {
 
   // A few properties are computed for a nicer API
   result.isEnabled = !addon.userDisabled;
+  result.canUninstall = Boolean(addon.permissions & AddonManager.PERM_CAN_UNINSTALL);
 
   return result;
 }

toolkit/mozapps/extensions/test/browser/browser_webapi.js

@@ -17,7 +17,7 @@ function testWithAPI(task) {
 
 let gProvider = new MockProvider();
 
-gProvider.createAddons([{
+let addons = gProvider.createAddons([{
   id: "addon1@tests.mozilla.org",
   name: "Test add-on 1",
   version: "2.1",
@@ -41,8 +41,18 @@ gProvider.createAddons([{
   type: "extension",
   userDisabled: true,
   isActive: false,
+}, {
+  id: "addon4@tests.mozilla.org",
+  name: "Test add-on 4",
+  version: "1",
+  description: "Longer description",
+  type: "extension",
+  userDisabled: false,
+  isActive: true,
 }]);
 
+addons[3].permissions &= ~AddonManager.PERM_CAN_UNINSTALL;
+
 function API_getAddonByID(browser, id) {
   return ContentTask.spawn(browser, id, function*(id) {
     let addon = yield content.navigator.mozAddonManager.getAddonByID(id);
@@ -67,6 +77,10 @@ add_task(testWithAPI(function*(browser) {
         case "isEnabled":
           realVal = !real.userDisabled;
           break;
+
+        case "canUninstall":
+          realVal = Boolean(real.permissions & AddonManager.PERM_CAN_UNINSTALL);
+          break;
       }
 
       // null and undefined don't compare well so stringify them first