Bug 1402085 P1 Maybe fire ServiceWorkerContainer.ready promise when a registration is resurrected. r=asuth

dom/workers/ServiceWorkerManager.h

@@ -336,6 +336,9 @@ public:
   void
   WorkerIsIdle(ServiceWorkerInfo* aWorker);
 
+  void
+  CheckPendingReadyPromises();
+
 private:
   ServiceWorkerManager();
   ~ServiceWorkerManager();
@@ -446,9 +449,6 @@ private:
   StorePendingReadyPromise(nsPIDOMWindowInner* aWindow, nsIURI* aURI,
                            Promise* aPromise);
 
-  void
-  CheckPendingReadyPromises();
-
   bool
   CheckReadyPromise(nsPIDOMWindowInner* aWindow, nsIURI* aURI,
                     Promise* aPromise);

dom/workers/ServiceWorkerRegisterJob.cpp

@@ -46,9 +46,14 @@ ServiceWorkerRegisterJob::AsyncExecute()
     // unregister so that closing the window by shutting down the browser
     // results in the registration being gone on restart.
     if (registration->mPendingUninstall) {
+      registration->mPendingUninstall = false;
       swm->StoreRegistration(mPrincipal, registration);
+      // Its possible that a ready promise is created between when the
+      // uninstalling flag is set and when we resurrect the registration
+      // here.  In that case we might need to fire the ready promise
+      // now.
+      swm->CheckPendingReadyPromises();
     }
-    registration->mPendingUninstall = false;
     RefPtr<ServiceWorkerInfo> newest = registration->Newest();
     if (newest && mScriptSpec.Equals(newest->ScriptSpec()) && sameUVC) {
       SetRegistration(registration);