Bug 1358160 - Get usage from subject instead of data field, r=Fischer

MozReview-Commit-ID: 5UNttoq1jiX

--HG--
extra : rebase_source : b629cf3c33b54fe9a20ceb6e7d996d71917757fe

browser/base/content/browser.js

@@ -468,7 +468,7 @@ const gStoragePressureObserver = {
       Services.prefs.getIntPref("browser.storageManager.pressureNotification.usageThresholdGB");
     let msg = "";
     let buttons = [];
-    let usage = parseInt(data);
+    let usage = subject.QueryInterface(Ci.nsISupportsPRUint64).data
     let prefStrBundle = document.getElementById("bundle_preferences");
     let brandShortName = document.getElementById("bundle_brand").getString("brandShortName");
     let notificationBox = document.getElementById("high-priority-global-notificationbox");

browser/base/content/test/general/browser_storagePressure_notification.js

@@ -4,7 +4,10 @@
 
 function notifyStoragePressure(usage = 100) {
   let notifyPromise = TestUtils.topicObserved("QuotaManager::StoragePressure", () => true);
-  Services.obs.notifyObservers(null, "QuotaManager::StoragePressure", usage);
+  let usageWrapper = Cc["@mozilla.org/supports-PRUint64;1"]
+                     .createInstance(Ci.nsISupportsPRUint64);
+  usageWrapper.data = usage;
+  Services.obs.notifyObservers(usageWrapper, "QuotaManager::StoragePressure");
   return notifyPromise;
 }